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Abaxial: - The side of an organ that faces away from the axis which bears it, e.g., the under surface of a leaf, the lower surface of the petiole, or the outer surface of a tubular bract.
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Abscission: - Separation, often by a distinct layer.
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Acanthophyll: - A spine, often large, derived from a leaflet.
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Acaulescent: - Without an above-ground stem or trunk.
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Acervulus: - A group of flowers borne in a line.
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Acetolysis / acetolyse: - A process that is used to clear pollen grains of their internal cellular fraction, the intine, and any external lipidic coatings. The acetolysis mixture comprises nine parts acetic anhydride and one part sulphuric acid.
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Acid (of soil): - With a pH value of less than 7. (Double click to see: pH, Alkaline, and Neutral)
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Acropetal (of flowering): - Progressing from the base towards the apex.
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Aculea: - Small spiny outgrowth.
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Aculeated: - Having or resembling a stinger or barb.
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Acuminate (of a leaf shape): - Narrowing to a slender point .
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Acute: - Sharply pointed, but without being drawn out to the point.
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Adaxial: - The side of an organ towards the axis that bears it; e.g., the upper side of a leaf, the upper surface of a petiole, or the inner surface of a tubular bract.
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Adjacent-ligular: - In germination, the new shoot developing next to the seed and enclosed by a ligule.
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Adnate: - Attached to, usually of one kind of organ to another kind, as bract to axis.
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Aerial root: - Grows above ground instead of below, usually supports the trunk, also called a "stilt root".
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Affinity: - State of relationship between organisms or groups of organisms resulting in resemblance in structure or structural parts.
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AFLP: - Amplified fragment length polymorphism, a type of DNA data used to study relationships among populations or species.
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Aggregate (abbreviated to agg.): - A group of closely related taxa which are treated together for recording purposes because the component segregates cannot always be identified.
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Albumen: - The endosperm of the seeds.
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Alien: - A plant which was introduced to an area by man, or arrived naturally from an area in which it was present as an alien. A synonym of introduction. Alien plants in the British Isles can be divided into archaeophytes and neophytes.
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Alkaline (of soil): - With a pH value of more than 7. (Double click to see: Acid, pH, and Neutral)
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Alternate: - First on one side and then on the other in two ranks along an axis; not paired; "stems with alternate leaves".
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Anastomose: - To unite, usually forming a network.
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Anatropous: - An ovule bent parallel to its stalk so that the micropyle is adjacent to the hilum.
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Androecium: - Collective term for the stamens.
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Anemophilous (of flowering plants): - (especially grasses etc) that are pollinated by the wind.
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Angiosperm: - A class of plants whose seeds are borne within the walls of an ovary.
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Anomalous: - Deviating from the general or common order or type.
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Anther: - Pollen-containing part of the stamen.
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Anthesis: - The time of flower opening, when the flower is ready for fertilisation, i.e., shedding of pollen or receptivity of stigma.
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Aperture: - see Germinal aperture.
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Apex (of leaves or leaflets): - The tip.
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Apical: - Situated at an apex.
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Apiculate (of a leaf shape): - Having a short, sharp but not stiff point.
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Apocarpous: - Consisting of carpels that are free from one another as in buttercups or roses.
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Apomixis: - Any of several kinds of reproduction without fertilisation.
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Arborescent: - Resembling a tree in form and branching structure.
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Archaeophyte: - A plant which was introduced to an area by man, or arrived naturally from an area in which it was present as an introduction, and became naturalised before AD 1500. (Double click to see neophyte)
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Arching (of leaves or leaflets): - Having a curved or arch shape, not erect.
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Arcuate: - Forming or resembling an arch.
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Arctic-montane: - A major biome category which includes plants occurring north of the tree-line or on mountains above the tree-line, or both.
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Aril: - An outgrowth of the stalk of the ovule, sometimes resembling a third integument.
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Ariled (of seeds): - Having a fleshy and usually brightly colored cover.
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Armament: - Protection; see also armed.
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Armed: - Bearing spines, sharp teeth, prickles etc.
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Articulate (of leaflets): - Having a narrowed base which tends to abscise before the leaf.
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Ascending: - Growing upward.
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Asymmetric / asymmetrical: - Without symmetry.
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Auricle: - An ear-like lobe.
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Axil: - The upper angle between a leaf stalk and a twig, a twig and a branch or a leaf vein and the midrib.
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Axillary: - Borne in an axil, which is the angle between the stem and the leaf or another organ that arises from the stem, such as a bract.
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Bark: - The skin. The outer layer of a woody plant that protects the inner tissues from damage and disease.
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Basifixed: - Attached by the base.
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Basipetal (of flowering): - Progressing from the apex towards the base.
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Bast: - The soft, often fibrous layer of phloem tissue between the bark and the inner cells.
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Bicarinate: - Having two keels.
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Bifid: - Divided or forked into two equal parts.
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Biome: - An area defined by its potential vegetation type, which is ultimately controlled by climate. North of the tropics, the major biomes form latitudinal belts (zonobiomes). However, these patterns are complicated by the presence of mountains, as increasing altitude has a similar affect to increasing latitude, leading to the presence (for example) of vegetation characteristic of both the Boreal biome at high altitudes in the Temperate biome.
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Bijugate: - Used for a pinnate leaf with two pairs of leaflets.
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Bipinnate (of leaves): - Doubly pinnate, the rachis itself dividing and the secondary rachis bearing leaflets.
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Bisexual: - Containing functional male and female parts.
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Bi-symmetric / bi-symmetrical: - With two planes of symmetry.
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Blade (of leaf): - Flat or expanded part of the leaf; the part that is palmate or pinnate in palms leaves.
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Bloom (coating): - A thin, waxy film covering the surface of a leaf or other part of a plant.
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Bole: - The trunk of a tree, usually the lower section.
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Bootstrap support: - An estimate of confidence in an individual clade within a phylogenetic tree. High bootstrap support indicates a high level of confidence that the clade will be resolved as new data are analysed. Low bootstrap support indicates a possibility that the clade may not be resolved by new data.
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Boreal-montane: - A major biome category which includes plants occurring in the coniferous forest zone, either in the Boreal zonobiome or on mountains further south, or both.
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Boreo-arctic Montane: - A major biome category which includes plants occurring in both the Arctic-montane and the Boreal-montane biomes.
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Boreo-temperate: - A major biome category which includes plants occurring in both the Boreal-montane and the Temperate biomes.
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Bract: - A modified leaf acting as a protective organ and associated with an inflorescence, a flower or with cycad cones.
A leaf-like structure beneath a flower or at the base of a stalk. Often seen on conifer cones. -
Bracteole: - A small bract borne on a flower stalk, often present even when the flower is essentially sessile (see also bract).
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Branching (of the inflorescence): - The flowering terms are used to describe the degree of branched - branching, not the number of branches.
Simple-branched or simply branched - branching to one order.
Moderate-branched or moderately branched - branching to two or three orders.
Well branched - branching to four orders. -
Bremer support: - A measurement of the reliability of an individual clade with respect to alternative hypotheses. Bremer support is negatively affected by conflict in a dataset, decreasing when alternative hypotheses are nearly as good as the best hypothesis.
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Brevisulcate: - Of a pollen grain having a very short sulcus.
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Broadleaved tree: - Often called hardwoods and usually with broader leaves than conifers, this large group, mostly dicotyledons, all belong to the group of plants called Angiosperms.
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Bulbous (of trunk): - Bulging, swollen, bulb-shaped.
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Cabbage: - Apical leaf bud of the crown, or 'heart of palm' (edible).
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Caducous: - Dropping off early or gradually.
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Caespitose: - Clustered, clumping, with several to many stems.
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Callose envelope: - Callose is a structural polysaccharide found in higher plants. It has a blocking function — in the early stages of pollen development, a thick layer of callose is deposited around each pollen mother cell (meiocyte) separating them from each other.
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Calyx: - The outermost or lower-most whorl of floral organs, the sepals.
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Cambium: - A layer of active cell division that produces new tissues, such as the vascular cambium that gives rise to new xylem and phloem tissue.
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Campo: - Extensive, nearly level, grassy plain in South America.
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Campylotropous: - An ovule curved with the micropyle close to the hilum and the embryo sac also curved.
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Cane: - Thin or reedlike stem or trunk.
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Capitate: - Head-like; in pollen, of columellae with expanded apices.
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Carpel: - The organ of the flower which encloses the ovules.
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Cataphyll: - A rudimentary leaf form, such as a scale.
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Catkin-like: - Describes a thick, cylindrical rachilla on which the flowers are densely crowded.
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Caudex: - Term often used for the trunk of cycads.
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Chartaceous: - Paper-like, thin and stiff.
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Ciliate: - Bearing a fringe of hairs.
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Cincinnus: - A flower cluster wherein each successive flower arises in the axil of a bracteole borne on the stalk of the previous flower.
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Circinate: - Rolled up into a circle or ring shape (in cross-section).
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Cirrate: - Bearing a cirrus.
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Cirrus: - A whip-like climbing organ with reflexed spines that is an apical extension of the leaf rachis (plural: cirri).
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Clade: - A monophyletic group. A branch on a phylogenetic tree.
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Clava / clavae / clavate: - A club-shaped element of the ectexine that is higher than 1 µm, with a diameter smaller than height and thicker at the apex than the base.
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Climber: - A plant that climbs using other plants or objects as support.
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Clump: - A group or cluster (see also clustering and suckering).
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Clustering: - Growing side shoots and developing into groups of stems (see also clumping and suckering).
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Coco-fibre: - A planting compost made from coconut husks.
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Columella / columellae: - A rod-like element of the ectexine supporting the tectum.
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Columellar layer: - Synonym of infratectum.
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Concolorous: - When two surfaces (usually leaves) are of the same colour.
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Coniferous tree: - Often called softwoods and usually with needle-like leaves, these trees belong to the primitive group of plants called Gymnosperms. They have woody fruit bodies called cones.
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Conical (of trunk): - Shaped like a cone.
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Connate: - United, used when organs of the same kind are joined, as sepals connate; see tubular calyx.
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Connective: - The part of a stamen that connects the anthers, usually distinct from the filament.
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Consensus tree: - A phylogenetic tree that summarises more than one hypothesis of relationships. A strict consensus tree only includes clades that are found in all hypotheses.
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Conservatory: - A greenhouse for tender plants.
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Container plant: - Grown in a container or pot instead of the ground, typical for nursery production.
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Copse: - A small wood or part of a wood, which is, or has in the past been regularly clear cut (Coppiced) & allowed to grow back from the original stumps.
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Coralloid (of roots): - Coral-like, always near the surface of the soil or just above the soil (characteristic of cycads).
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Coriaceous: - Leathery.
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Corolla: - The second whorl of flower organs, the petals, inside or above the calyx.
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Cortex: - The ground tissue between the vascular cylinder and the epidermis.
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Costa: - An extension of the petiole into the blade of a palmate leaf.
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Costapalmate (of the leaf shape): - Shaped like a fan or the palm of a hand, with a midrib which is an extension of the petiole.
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Cotyledon: - The first leaf or leaves that emerge from a seed.
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Crenulate: - Shallowly scalloped or bearing rounded teeth.
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Crotonoid: - A characteristic type of ectexine ornamentation comprising rings of five or six (sometimes more) raised, often triangular, elements arranged around a circular area, usually formed by capitate columellae.
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Crown: - The cluster of leaves at the top of the stem.
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Crownshaft: - The cylinder-shaped collection of tubular leaf sheaths at the to of the stem, each sheath wrapped around the one beneath.
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Cultivar: - A variant of a cultivated plant, produced through asexual reproduction. Cultivars may be given special names, which are cited within inverted commas, e.g. Brachyglottis 'Sunshine'.
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Cultivate: - To grow or raise, aided by humans.
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Cuticle: - A layer of wax covering the epidermis.
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Cupule: - A small cup-like structure.
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Cytokinesis: - The process of cytoplasmic division.
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Deciduous: - Losing leaves in winter.
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Decompound (of leaves): - To compound (divide) a second or further time.
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Decumbent (of stems): - Reclining, but with the apex turned upwards.
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Decurrent (of leaves): - The lower margins extending along the rachis and near-parallel to the rachis. In cycads, decurrent leaflets are less likely to abscise before the leaf itself.
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Decussate tetrad: - A multi-planar tetrad of pollen grains or spores arranged in two pairs lying across one another, more or less at right angles.
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Deltoid: - Shaped like an equilateral triangle.
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Dentate: - Toothed.
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Determinate: - Bearing a terminal organ, as in an inflorescence when a branch ends in a flower bud.
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Dichotomous: - Forking (of stem, root etc.) into two equal branches.
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Dicotyledon: - A plant having two cotyledons (Double click to see Monocotyledon).
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Didymous: - Of anthers where the connective is almost absent.
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Digitate: - Like fingers.
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Dimorphic: - With two different forms.
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Dioecious: - Unisexual, of one sex only. When staminate and pistillate (male and female) flowers are borne on different plants.
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Diporate: - Of a pollen grain having two pori (germinal apertures).
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Discolorous: - When two surfaces (usually leaves) are of a different colour. (c.f. concolorous)
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Distal: - Situated farthest away from the place of attachment.
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Distal disulcate: - Of a pollen grain with paired sulci lying parallel to the long axis of the pollen grain on the distal face.
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Distant: - Widely separated.
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Distichous: (of leaf arangement) - Arranged in two opposing rows on either side of a trunk.
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Disulcate: - Of a pollen grain having two sulci (germinal apertures). In palms, usually positioned on the short equatorial faces of the pollen grain but see also 'distal disulcate'.
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Divaricate (of branching): - Spread widely.
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Divided (of leaves): - Not entire.
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Dorsifixed: - Attached by the abaxial (usually outer) side.
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Dwarf: - Small or undersized.
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Dyad (of flowers): - A pair.
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Ectexine: - The outer layer of the pollen exine, in TEM, it has higher electron density than endexine.
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Ellipsoidal: - Shaped like a solid ellipse.
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Elliptical: - Shaped like an ellipse. Oblong with regularly rounded ends.
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Emarginate: - With a notch cut out, often at the apex.
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Embryo: - The rudimentary plant present in a seed.
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Endemic: - Restricted in distribution to a particular area. (Only that area. No other).
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Endexine: - The inner layer of the pollen exine, it has lower electron density than ectexine.
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Endocarp: - The innermost layer of the fruit wall that encloses the seed.
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Endosperm: - The energy storage tissue of the seed. Which is used for the developing embryo and seedling.
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Entire: (of leaves) - Undivided, whole.
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Eophyll: - First seedling leaf.
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Epicarp: - The outermost layer of the fruit wall.
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Epipetalous: - United with, often appearing to be borne on, the petals.
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Equator / equatorial: - The dividing line between the distal and proximal faces of a pollen grain or spore.
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Erect (of leaves or trunk: - Stiffly upward or upright.
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Established: - Used to describe a population of alien plants which has persisted in an area for at least five years, spreading vegetatively or reproducing by seed. A synonym of naturalised.
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Exine: - The outer usually sporopollenin layer of a pollen grain, which has an important protective function during pollen transfer from anther to stigma.
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Exotic: - Originally, this term was used for all plants which came from the newly discovered lands, everywhere from the arctic to the tropics. Nowadays, it is usually used to describe plants which come only from the tropical or sub-tropical climates.
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Exposed columellae: - Columellae not overlain by a tectum, usually in the form of spines or clavae in intectate pollen.
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Extended sulcate: - Of a pollen grain having a single sulcus, the apices of which extend beyond the equator towards the proximal face.
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Extremophile: - An extremophile is an organism, which thrives in or requires "extreme" conditions.
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Extrorse: - Of anthers, opening abaxially, away from the centre of the flower.
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Falcate: - With one margin longer than the other: sickle-shaped.
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Feather (of leaf): - Pinnate, divided in segments like a feather.
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Fenestrate: - With holes or openings, sometimes like windows.
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Fibrous: - Having or made up of fibres.
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Filament: - Of a stamen, the stalk which bears the anther.
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Filamentous: - Thread-like.
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Fissured: - Having clefts or splits.
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Flabellate: - Fan-shaped or wedge-shaped.
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Flagellum: - A whip-like climbing organ formed from a modified inflorescence (plural: flagella).
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Flange: - A flat ridge or protrusion; also called a wing.
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Flexuous: - Lax or flexible.
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Floccose: - Bearing soft, uneven hairs or scales.
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Flora: - As a collective name for plants occurring in a specific geographical area.
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Flower: - The reproductive organ of a plant.
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Flush: - Fresh, new growth.
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Foot layer: - The inner layer of the ectexine.
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Forked: - Divided into two equal parts.
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Foveola / foveolae / foveolate: - Large rounded holes or depressions (lumina) in or through the tectum, which are too large to be described as perforations (>1 µm in diameter), separated by broad areas of tectum similar in width, or wider than, the foveolae.
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Frond: - Leaf of a non-flowering plant such as a fern or cycad.
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Fruit: - Seed-bearing organ.
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Funiculus: - The stalk of an ovule.
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Gamo: - As a prefix, united or fused (see sepals and petals).
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Gemma / gemmae / gemmate: - Sexine elements that are constricted at the base, higher than 1 µm, and approximately the same width as height.
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Genus: - The usual major subdivision of a family or subfamily, usually consisting of more than one species. The species which make up the genus are very closely related. The genus designation is the first part of a scientific name of a species (plural: genera).
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Germinal aperture: - The functional opening, covered by an aperture membrane in vivo, through which the pollen tube emerges (in palms a sulcus or pore).
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Germinate: - To sprout a seed.
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Gibbous: - More convex on one side than another, as a not quite full moon.
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Glabrous: - Smooth-surfaced, without hairs or scales, etc.
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Glaucous: - Covered with wax, giving a grey or bluish-grey bloom.
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Glomerule: - A knob-like cluster of flowers (such as in Livistona spp.).
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Granulae / granular: - General word for small rounded elements.
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Grapnel: - A small anchor or hook with three or more flukes.
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Gymnosperm: - A class of primitive plants that are 'naked seeded', their seeds being exposed on a scale and not concealed in an ovary.
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Gynoecium: - The ovule-bearing organ of the flower, composed of one to several carpels and divisible into an ovary, a style, and one or several stigmas.
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Habit: - Mode of growth.
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Habitat: - The natural environment in which a plant grows.
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Hapaxanthic (of stems): - Those stems that flower only one and then die.
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Haploid: - A nucleus or individual containing only one representative of each chromosome of the chromosome complement.
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Hardy: - Able to withstand the local, year-round climatic conditions, including frost, without protection.
Half-hardy: Used of a plant not tolerating frost in a given climatic zone. The term generally implies an ability to withstand lower temperatures than tender. -
Hastula: - An outgrowth of flap of tissue at the insertion of the blade on the petiole (in palmate leaves).
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Hemianatropous: - An ovule turned so that the micropyle is at right angles to its stalk (funiculus).
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Hermaphrodite: - Flowers having both stamens and gynoecium.
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Heteropolar: - Pollen grains or spores where the distal and proximal faces differ; for example, in the monosulcate pollen grains of palms.
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Hilum: - The scar left on the seed where it was attached.
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Homogeneous (of seed endosperm): - Uniform throughout, without interruptions of the seed coat into the endosperm (Double click to see ruminate).
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Humus (of soil): - Decomposing organic matter.
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Hybrid: - A plant resulting from the cross between plants of two different taxa, such as between two species of the same genus, between two species of different genera, or between two subspecies of the same genus.
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Imbricate: - To overlap, cf. 'valvate'.
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Imparipinnate: - Unevenly pinnate, bearing a terminal leaflet.
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Impression mark: - A mark on the proximal face of the pollen grain retained from the post-meiotic stage. This mark can be linear from tetragonal or decussate tetrads or Y-shaped from tetrahedral tetrads.
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Inaperturate: - Without a germinal aperture.
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Incomplete equatorial: - Of a pollen grain having a very elongated (extended) sulcus, extending almost completely around the equator so that the apices all but meet.
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Indeterminate: - Not bearing a terminal flower or other organ.
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Indumentum: - A covering of hairs or scales.
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Induplicate (of leaflets): - V-shaped in cross-section.
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Inflexed: - Bent or curved inward toward the centre.
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Inflorescence: - That part of the plant which includes all the flowering branches.
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Infrafoliar: - Borne below the leaves.
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Infraspecific taxon: - Any taxon below the rank of species (e.g. subspecies, variety).
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Infratectum: - A general term for the ectexine layer beneath the tectum, and above the foot layer.
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Infructescence: - The same parts as the inflorescence, but when they are in fruit.
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Intectate: - Without a tectum but with sculptural elements.
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Integument: - A covering or envelope enclosing the ovule.
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Interandean: - Dry, high altitude valleys between the main ridges of the Andes mountains in South America.
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Interfoliar: - Borne among the leaves.
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Internal cellular fraction: - The internal part of the pollen grain including the generative and vegetative cells and surrounding cytoplasm and organelles.
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Internode: - The stem between the point of attachment of two leaves.
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Interrupted reticulum / reticulate: - A reticulum where the muri are not continuous, as in a net, but appear 'broken up' or fragmented.
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Intersegmental fibres: - Fibres resulting from disintegration of the ribs between the segments of palmate leaves.
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Intine: - The inner layer, of the pollen grain wall ('sporoderm'), which has an important protective function during pollen germination and pollen tube growth.
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Introrse: - Of anthers, opening toward the centre of the flower.
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Introduction: - A plant which was introduced to an area by man, or arrived naturally from an area in which it was present as an introduction. A synonym of alien. Introductions in the British Isles can be divided into archaeophytes and neophytes.
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Involute: - Rolled inwards from the edge.
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Irregular (of arrangement of leaflets): - Leaflets not arranged directly opposite on either side of the leaf rachis.
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Jacknife support: - An estimate of confidence in an individual clade within a phylogenetic tree. See Bootstrap support for interpretation of support values.
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Keeled: - Bearing a ridge, like the keel of a boat.
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Knee (in rattan palms): - A swelling on the leaf sheath at the base of the petiole.
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Lamellae / lamellar: - A general term for a thin layer - in palm pollen, these layers refer to a lamellated foot layer as in Calamoideae, they are unusual elsewhere in the family.
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Lamina (of leaf): - Surface of the blade.
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Lanceolate (of leaf or leaflet): - Narrow and tapering at both ends.
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Latrorse: - Of anthers, opening lateral to the filament.
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Leaflet: - Division of a pinnate leaf (Double click to see pinna).
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Leathery: - Having a texture like leather, thick and strong.
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Lignin: - The chemical impregnated in the cell walls of xylem tissue and giving wood its basic characteristics.
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Ligule: - A distal projection of the leaf sheath.
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Linear (of leaf or leaflets): - Very narrow, many times longer than wide, with the sides parallel or nearly so.
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Lipid-based coatings: - pollenkitt/pollen coat - sticky material produced by the tapetum that is considered to have a range of probable functions.
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Locule: - The cavity in which the ovule is borne.
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Lowland: - Used in the descriptions of the altitudinal range of species to indicate altitudes between sea-level and 300 m (Double click to see Montane, Upland).
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Lumina / lumen: - The space(s) enclosed/surrounded by the muri in a reticulate ectexine.
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Marbled: - Showing various colors in blotches; mottled.
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Marcescent: - Withering before being shed.
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Median (of leaves): - At or about the middle section of the rachis.
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Medifixed: - Attached at the middle.
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Mediterranean-Atlantic: - A floristic element which includes plants which are confined to the Southern biome in eastern Europe but extend into the Temperate biome in western Europe, and thus tend to occur along the Mediterranean and Atlantic seaboards.
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Mediterranean-montane: - A floristic element which includes plants which in Europe have a Montane distribution in the Southern biome but occur at low altitudes in Temperate regions.
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Megasporophyll: - Structure on the female cycad plant containing the ovules.
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Meristem: - The growing region of a plant, a special area of undifferentiated cells wherein new cells and organs are developed.
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Mesocarp: - The middle layer of the fruit wall, usually fleshy or fibrous, sometimes oily.
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Mesophyll: - The inner tissue of a leaf.
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Midrib (of leaves): - The main vein of a leaf.
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Micro-channels: - Small channels in the tectum that penetrate to the infratectum.
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Micro-fossulae: - Channel-like indentations in the tectum that do not penetrate to the infratectum.
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Micropyle: - An aperture through the integuments of the ovule.
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Microsatellites: - Regions of repetitive DNA that are highly variable and useful for genetic analyses of populations or species.
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Microsporogenesis: - In pollen, the development from the sporogenous tissue of the anther to maturity as (usually) individual pollen grains.
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Microsporophyll: - Structure on the male cycad plant containing the pollen.
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Mitochondrial DNA: - DNA within mitochondria, which are organelles found inside the cells of plants and many other kinds of organisms.
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Moderate: - Medium or intermediate in size.
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Monocarpic: - Fruiting only once before dying.
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Monocotyledon: - A plant having one cotyledon (Double click to see Dicotyledon).
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Monoecious: - Bearing both staminate and pistillate (male and female) flowers on the one plant.
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Monomerous: - Formed of a single member.
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Monophyletic group: - A taxonomic group that includes all descendants of a common ancestor. A branch on a phylogenetic tree. Monophyletic groups are the basis of modern, phylogenetic classifications.
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Monopodial: - With a single main axis.
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Monoporate: - Of a pollen grain, having a single, presumed distal, pore (germinal aperture).
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Monosulcate: - Of a pollen grain, having a single sulcus (germinal aperture).
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Monotypic (of a genus, family etc.): - Containing only one species.
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Morphology/morphological: - The study of form, particularly of external structures - the introduction of the word is attributed to the poet and botanist Johann Wolfgang von Goethe.
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Montane: - Used in the descriptions of the altitudinal range of species to indicate altitudes above 600 m (Double click to see Lowland, Upland).
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Mottled: - Having blotches of various colors; marbled.
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Muri / murus: - A continuous ridge that separates the lumina of a reticulate ectexine.
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Mulch: - Top dressing (wood chips, peat, straw, leaves, etc.) around a plant's roots.
To apply a top dressing -
Native: - A plant which arrived in our area without the intentional or unintentional intervention of man (Double click to see Alien, Introduced).
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Naturalised: - Used to describe a population of alien plants which has persisted in an area for at least five years, spreading vegetatively or reproducing by seed. A synonym of established.
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Neophyte: - A plant which was introduced to an area by man, or arrived naturally from an area in which it was present as an introduction, and became naturalised after AD 1500. (Double click to see archaeophyte)
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Neutral (of soil): - With a pH value of 7, i.e. neither acid nor alkaline. (Double click to see: Acid, Alkaline, and pH)
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Nodding (of leaves): - Drooping.
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Node: - That point on a stem where the leaf is or was attached.
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Notched (of a leaf or leaflet): - A cut or indentation in the edge.
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Nuclear DNA: - The majority of DNA found in plant cells, located within the nucleus.
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Nucleotide substitution: - A mutation that replaces one nucleotide in a segment of DNA with another. When present in more than one taxon, these mutations may provide evidence of phylogenetic relationship.
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Oblate: - ± spherical but flattened at the poles; of pollen, a rather flattened spheroidal or trianguloid pollen grain.
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Obovoid: - Egg-shaped, broader distally.
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Obpyriform: - Pear-shaped but attached at the broad end.
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Ocrea: - An extension of the leaf sheath beyond the point of insertion of the petiole.
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Ontogeny: - The development of an individual through its various stages.
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Operculum: - A lid or cover; in pollen, a distinctly delimited ectexinous lid-like structure that covers all or part of an aperture.
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Orbicular (of leaf): - Spherical or circular, like an orb.
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Orbicule / orbiculae (or Ubisch body): - A distinctive granule, usually orbicular, of sporopollenin produced by the tapetum. These may be deposited on the outer exine of maturing pollen grains.
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Order (and its extensions, first, etc.): - A sequence, as of branching: a first-order branch branches to produce a second-order branch, etc. Orthotropous - an erect ovule with the micropyle distal and hilum basal.
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Ornamental: - A term used to describe plants, which are planted for their architectural, specimen, or landscape qualities, as opposed to being planted for food or commercial purposes.
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Ovary: - The ovule-bearing part of the gynoecium.
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Ovoid: - Egg-shaped.
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Ovate: - Egg-shaped.
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Ovule: - The young or developing seed.
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Palman : - The undivided central part of a palmate leaf.
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Palmate: - Shaped like the palm of a hand, with ribs or veins radiating from one point.
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Panicle: - An inflorescence with many branches, in which each successive branch becomes smaller.
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Paniculate: - Descriptive of an inflorescence that is a panicle.
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Papillose: - Bearing nipple-like projections.
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Paraphyletic: - A taxonomic group that includes some, but not all descendants of a common ancestor.
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Paripinnate: - Evenly pinnate, lacking a terminal leaflet.
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Parsimony: - A criterion for choosing among different hypotheses of relationships. Parsimony favours the hypothesis that offers the simplest explanation for observed data.
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PCR: - Polymerase chain reaction, a process that allows specific DNA regions to be targeted and copied for many types of genetic analysis, including sequencing.
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Peat: - Decomposed peat moss, partly carbonised.
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Pectinate: - With teeth like a comb.
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Pedicel: - A floral stalk.
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Peduncle: - The lower unbranched stalk of an inflorescence.
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Peduncular bracts: - Empty bracts on the main inflorescence axis between the prophyll and the first rachis bract.
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Pendent: - Drooping.
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Pendulous: - Drooping, suspended, hanging vertically.
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Peltate (of leaves): - Having a petiole attached to the lower surface at a distance from the margin.
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Perforate / perforation: - In pollen morphology, applied to holes through the tectum of less than 1 µm in diameter.
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Perianth: - The sepals and the petals together.
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Pericarp: - The walls of the fruit: epicarp, mesocarp and endocarp.
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Persistent: - Applied to a plant parts that remain attached to the plant after they (the parts) die or cease to function.
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Petal: - One unit of the inner floral envelope or corolla.
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Petiole: - The leaf stalk, below where the leaflets are attached and above the leaf sheath (Double click to see rachis).
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Phloem: - Vascular tissue that transports food materials made by the plant.
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pH: - A measure of alkalinity or acidity, used horticulturally to refer to soils. The scale measures from 1 to 14; pH7 is neutral, above 7 is alkaline, and below 7 acid. (Double click to see: Acid, Alkaline, and Neutral)
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Photosynthesis: - The process by which carbohydrates are synthesised from carbon dioxide and water in the presence of sunlight.
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Phylogeny: - A hypothesis of relationships that can be expressed in the form of a branching diagram or tree (phylogenetic tree).
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Phyllode: - A flattened stem which looks and functions like a leaf.
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Phytosanitary certificate: - Issued by our agricultural inspectors DEFRA and accompanies a shipment of seeds or plants to declare thier apparent freedom from harmful organisms such as insects, fungus, etc.
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Pinna: - Term sometimes used instead of leaflet (plural: pinnae).
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Pinnate (of a leaf): - Leaflets or lateral ribs arranged on each side of a central axis, feather-like.
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Pinnule (of leaves): - The secondary leaflet of a bipinnate leaf.
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Pistillate: - Bearing a pistil (gynoecium), the ovule-bearing organ of the flower.
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Pistillode: - A sterile gynoecium.
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Pit: - A cavity formed by united bracts, enclosing flowers.
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Pith: - The parenchymatous or often spongy centre of a stem.
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Plastid DNA: - DNA within plastids, a class of organelles found in plant cells.
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Pleonanthic (of stems): - Those that flower more than once, not dying after one flowering.
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Plicate: - Folded into pleats.
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Plumose: - Having a feathery, bushy appearance.
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Pneumatophores: - Above-ground, 'breathing' roots that allow gas exchange in habitats with inundated or waterlogged soil.
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Podsol: - A zoned soil with a layer of humus overlying an acidic, highly leached layer, and a basal layer with iron deposition.
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Polar / polarity: - The condition of having distinct poles. Polarity of pollen grains is determined by their orientation at tetrad stage or by inference from the distribution of apertures and other features.
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Pollen: - Plant 'sperm'.
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Pollination: - The transfer of pollen from the male parts pf a flower (anther) to the female part (stigma).
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Polygamo-dioecious: - Bearing hermaphrodite and either male or female flowers.
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Polyphyletic: - A taxonomic group that does not have a single recent common ancestor. Two or more unrelated branches on a phylogenetic tree.
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Pontoperculate / pontoperculum: - A type of operculum that is not completely isolated from the remainder of the ectexine, but linked to it between the ends of the apertures as in Chamaerops and Iriartella.
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Porate: - Of a pollen grain, having one or more germinal pores.
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Poricidal: - Opening by pores.
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Praemorse: - Jagged-toothed.
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Prickle: - Epidermal projection that is spine-like.
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Prophyll: - The first bract borne on the inflorescence.
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Prostrate: - Lying flat.
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Protandrous: - Of flowers or inflorescences, pollen shed before the stigma is receptive.
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Protogynous: - Of flowers or inflorescences, the stigma receptive before the pollen is shed.
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Proximal: - Situated closest to the place of attachment.
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Pseudomonomerous: - Appearing to be of one member but actually of several, as a gynoecium with one fertile carpel and one locule but parts of two other carpels present.
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Pseudostem: - Literally 'false stem', looks like a stem but is actually tightly packed leafbases.
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Pseudotrunk: - Literally 'false trunk', looks like a trunk but is actually tightly packed leafbases.
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Psilate: - Smooth.
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Pubescent: - Hairy.
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Punctiform: - Dot-like.
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Pyrene: - A seed-like body formed by a hard, often sculptured layer of endocarp that surrounds the seed.
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Pyriform: - Pear-shaped.
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Pytxis: - Young, emerging foliage leaf.
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Rachilla: - The branch that bears the flowers (plural: rachillae).
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Rachis: - That part of the leaf from which the leaflets arise, that is, the axis of a leaf beyond the petiole (Double click to see petiole, sheath).
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Radicle: - The first root developed from an embryo.
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Ramenta: - Rather thin scales with ragged edges, often large and irregular in shape.
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Rank: - A row, usually a vertical one.
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Raphe: - A ridge or depression on the seed, usually the source of fibrovascular branches.
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Raphides: - Bundles of needle-shaped crystals of calcium oxalate..
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Recurved: - Curved backwards.
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Reduplicate (of leaflets): - Upside-down V-shaped in cross-section.
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Reflexed: - Curved backwards.
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Regular (of arrangement of leaflets): - Leaflets arranged in pairs directly opposite on either side of the leaf rachis.
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Rein: - Threadlike tissue connecting the leaftips of developing leaves in pinnate palms.
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Remote-ligular: - In germination, the young plant connected to the seed by a long tubular cotyledonary petiole, bearing a ligule.
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Remote-tubular: - In germination, the young plant connected to the seed by a long tubular cotyledonary petiole, lacking a ligule.
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Relict: - A primitive survivor from earlier times; a 'living fossil'.
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Resin: - The sticky sap exuded by many trees.
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Resolution: - An arrangement of taxa in a phylogenetic tree, e.g., "Tribe Caryoteae is resolved within subfamily Coryphoideae." Also used to indicate the level of ambiguity in a phylogenetic hypothesis, e.g., "Relationships within tribe Areceae are poorly resolved."
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Reticulum / reticulate: - Large rounded or, more frequently, angular holes (lumina) through the tectum. Unlike foveolae, the lumina are separated by areas of tectum (muri) that are narrower than the lumina; the overall appearance is net-like.
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Revolute: - Rolled under (backwards) towards the underside.
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RFLP: - Restriction fragment length polymorphism, a type of DNA data used to study phylogenetic relationships at all taxonomic levels.
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Rheophyte: - A plant adapted to growing in or on the banks of fast-flowing rivers; leaflets of rheophytic palms are usually very narrow, often linear.
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Rhizome: - Underground stem.
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Ribosomal DNA: - Regions of repetitive DNA that encode structural RNA molecules involved in protein synthesis.
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Ringed (of palms): - Having nodal scars.
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Rootstock: - A plant used to provide the root system for a grafted plant.
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Rotund: - Rounded.
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Rugose: - Wrinkled.
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Rugulae / rugulate: - Wrinkled.
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Ruminate (of endosperm or seed): - Streaked due to indentations of the seed coat into the endosperm.
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Runners: - Long, extended rhizomes.
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Sagittate: - Enlarged at the base into two acute, straight lobes like the barbed head of an arrow.
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Sarcotesta: - A fleshy layer developed (in palms) from the outer seed coat.
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Savanna: - Dry tropical or subtropical grassland or very open forest.
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Scabrate: - Of pollen roughened or with elements smaller than 1 µm.
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Scale: - Dry, flattened plates.
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Scurfy: - With small, flattened, papery scales.
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Seed: - The ripened, fertilized ovule containing a dormant embryo capable of developing into an adult plant.
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Seedling: - A very young plant, recently germinated.
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Segment (of leaves): - A division of a palmate leaf.
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Segregate: - An individual member of an aggregate.
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Semitectate: - A partial tectum in which tectal interruptions to the infratectum are wider than the surrounding tectum (e.g., reticulate).
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Senescent: - Growing old: becoming dysfunctional due to age.
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Sensu lato (abbreviated to sens. lat.): - Applied to a taxon which is interpreted 'in the broad sence', i.e. as including two or more closely related taxa (Double click to see Sensu stricto).
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Sensu stricto (abbreviated to sens. str.): - Applied to a taxon which is interpreted 'in the narrow sence', i.e. as excluding closely related taxa (Double click to see Sensu lato).
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Sepal: - A single part of the outermost whorl of floral organs the calyx.
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Seral: - A temporary or developing vegetation type.
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Serrate: - Toothed like a saw.
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Sessile: - Without a stalk.
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Sigmoid: - S-shaped.
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Sheath (of the leaf): - The base of the leaf that wraps around the stem. It is always tubular at first, but may split while or after it matures (Double click to see rachis, petiole).
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Shrub: - A woody-stemmed plant, usually branched from or near the base, lacking a single trunk.
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Shuttlecock (of palms): - Looking like a feather-duster.
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Sigmoid: - S-shaped.
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Simple (of leaves): - Undivided.
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Sinker (of plam roots): - The elongated leaf stalk of the first leaf (shoot) produced in some palms after germination, whose purpose is to push the plant down into the soil.
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Sinuous: - Wavy.
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Solitary (of plam stem ot trunk): - Not suckering, only producing a single stem.
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Southern: - A major biome category which includes plants occurring in the warm-temperate zone south of the broad-leaved deciduous forest zone. In Europe the Southern zone is the Mediterranean region.
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Southern-temperate: - A major biome category which includes plants occurring in both the Temperate and the Southern zones.
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Spadix: - In palms, the whole inflorescence. Not used because of ambiguities with other families.
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Spathe: - Sheathing bract that encloses and protects the young flower stalk.
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Spatulate: - Shaped like a small spatula, oblong with an extended basal part.
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Species: - The basic category of classification designated to signify a single kind of plant or animal. The species designation is the second part of the scientific name of a species (Double click to see genus).
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Spicate: - Spike-like, the inflorescence when it is not branched.
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Spicule: - A very slender brittle, needle-like spine.
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Spike: - Inflorescence, usually unbranched.
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Spine: - Sharp projection. Also used in pollen morphology for long, usually tapering elements; in palm pollen, length is defined as >2 µm.
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Spinulae / spinulose: - Small pointed elements extending from the tectum or foot layer (in intectate pollen); in palm pollen, height is defined as <2 µm.
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Spinules: - Very small spines; in pollen, small pointed elements extending from the foot layer or tectum; in palm pollen, height is defined as <2 µm.
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Spontaneous hybrid: - A hybrid which arises by natural cross-pollination, rather than a hybrid which is introduced or one which arises by deliberate pollination by man.
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Sporophyll: - Modified leaf structure carrying the reproductive parts in cycads.
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Sporopollenin: - The material comprising the tough outer pollen wall of most flowering plants. It comprises carbon, hydrogen and oxygen in an approximate ratio of 4:6:1. Recent results confirm the presence of fatty, aromatic and minimal carboxylic acid components. Although the components are consistent, the ratio of the components is apparently not consistent through all plant groups. Sporopollenin is probably "a randomly cross-linked biomacromolecule without a repetitive large-scale structure" and, furthermore, this is "a characteristic which would inherently make this material resistant to enzymic attack, as well as to many laboratory procedures designed to reduce/return it to its principle components". This being so would account for the extraordinary preservational qualities of pollen exine.
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Spreading (of crown): - Expansive, not upright.
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Sprout: - Germinated seed.
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Spur: - A short, often curved and tapered projection (such as in Kerriodoxa spp.).
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Stamen: - The male organ of a flower; a stalk or filament bearing an anther containing pollen.
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Staminate: - Bearing stamens, the pollen bearing organs of a flower.
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Staminode: - A vestigial stamen often greatly modified in form.
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Stem: - The main axis of a plant; trunk.
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Stigma: - The pollen receptor on the gynoecium, usually distal.
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Stilt root: - A prop root, grows above ground instead of below and supports the trunk (also see: aerial root).
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Stipule: - One pair of lateral outgrowths or appendages at the base of a petiole.
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Stock: - There are generally 3 uses for this term in horticulture:
1) The stock in store (product merchandise).
2) A plant used to obtain seed and propagation material.
3) And a rootstock (Double click to see). -
Stolon: - Above-ground, prostrate stems that usually roots at the nodes.
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Stoloniferous: - Describing stems that grow as stolons.
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Stratification: - The process of planting seed in moist sand and exposing it to low temperatures to trigger germination (over wintering).
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Striate: - Lined; in pollen, narrow, elongate, closely set and generally parallel elements of the tectum.
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Stomata: - Pores in the surface of leaves for the exchange of gases.
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Style: - The often attenuate part of a carpel or gynoecium between the ovary and the stigma.
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Sub: - As a prefix, meaning nearly or almost, e.g., subopposite equals nearly opposite.
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Subcanopy: - Plants in a forest that grow taller than the understorey but do not quite reach the canopy.
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Subequatorial: - Of pollen below the equatorial line, towards the proximal face.
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Subfalcate: - Nearly, or almost, falcate.
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Subterranean: - Underground.
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Submediterranean: - A floristic element which includes plants which are widespread in the Southern biome in eastern Europe and the Southern and Temperate biomes in western Europe. Members of this floristic element have more extensive distributions than the species in the Mediterranean-Atlantic element.
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Subtropical: - A climatic region between temperate and tropical.
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Subulate: - Awl-shaped.
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Succulent: - A plant with thick, fleshy leaves and/or stems adapted to store water.
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Sucker: - A shoot arising from below soil level close to the parent plant.
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Sulcus / sulci: - An elongate aperture usually situated either at the distal long axis face of the pollen grain or, less commonly, at the equatorial short axes of the pollen grain.
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Supratectate: - Above the tectum: for elements on top of, but attached to, the tectum.
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Syncarpous: - With united carpels.
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Symmetric: - With at least one plane of symmetry.
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Sympatrically: - Growing in the same or overlapping areas.
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Sympodial: - A stem made of superimposed branches, lacking a single main axis.
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Syncarpous: - With united carpels.
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Taproot: - A thick root that grows vertically into the soil to tap a source of water.
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Taxon: - Term used to denote any taxonomic category, such as species, genus, etc (plural: taxa).
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Tectate: - With a tectum.
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Tectum: - The uppermost layer of the ectexine, usually subtended by an infratectum.
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Temperate: - A major biome category which includes plants occurring in the cool-temperate broad-leaved deciduous forest zone.
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Tender: - Of a plant that is vulnerable to frost damage. (Double click for Hardy)
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Terete: - Circular in cross-section, usually cylindrical.
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Testa: - The outer coat of the seed.
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Tetrachotomosulcate / tetrachotomosulcus: - Of pollen having a four-armed sulcus.
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Tetrad: - A group of four united pollen grains or spores, either as a developmental stage or as a dispersal unit.
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Tetragonal tetrad: - A uniplanar tetrad in which all four members are in contact at the centre of the tetrad so that, in correct orientation, the adjacent walls form a cross.
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Tetrahedral tetrad: - A multiplanar tetrad in which each of the four members is in contact with the other three members, so that the centres of the grains define a tetrahedron.
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Thecae: - The locules of an anther.
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Thermophile: - A thermophile is an organism - a type of extremophile - which thrives at relatively high temperatures.
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Tolerant: - Suggests a plant will tolerate conditions for a limited period of time but is not necessarily "hardy" towards those conditions (see also hardy).
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Tomentose: - Covered with tomentum.
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Tomentum: - Covering of felt-like, dense short hairs, scales, wool or down.
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Toothed (of leaf or leafstalk: - With toothlike edges.
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Topology: - The arrangement of branches on a phylogenetic tree.
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Transpiration: - The loss of water from a plant by evaporation, especially through the stomata.
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Trebrown: - Trebrown is the name of the farm where our nursery is located. This is the anglicised version of the Cornish name Tre-Bron, meaning "settlement by the hill" The hill in question is a bronze-age hill fort. For those of you interested further; The Trebrown Nurseries logo depicts the hill.
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Tree: - A woody, perennial plant, which has a definite trunk or stem with a head or crown of branches above. Usually, taller than a man.
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Triad: - A cluster or group of three flowers, one female flanked by two males.
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Trichotomosulcate / trichotomosulcus: - Of pollen having a three-armed sulcus.
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Trijugate: - Bearing three pairs of leaflets.
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Trilocular: - Having three chambers, each usually bearing an ovule or seed.
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Triovulate: - Gynoecium with three ovules, one in the locule of each carpel.
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Triporate: - Of pollen having three pores.
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Tristichous (of leaf arrangement): - Arranged in three vertical rows on a trunk.
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Tropical: - Roughly, a climatic area where the daily amplitudes of temperature are greater than the yearly amplitudes. Geogaphically located roughly between the Tropic of Cancer in the north and the Tropic of Capricorn in the South.
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Truncate (of leaflets): - The apex appearing as though cut off nearly straight across.
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Trunk: - Stem.
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Trunkless: - Without a trunk or with a subterranean trunk.
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Tubercles: - Short, stout, persistent floral stalks, appearing as small humps, in coryphoid palms.
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Ultrastructure / ultrastructural: - Structural details of cells above the limit of resolution of the light microscope, and only revealed by electron microscopy.
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Undergrowth: - The lowest layer of plants in a forest.
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Understorey: - Lower layers of plants in a forest that do not reach the canopy and are shade loving.
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Undivided (of leaves: - Entire, whole, not broken down into segments or leaflets.
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Undulate: - Wavy.
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Unilocular: - With a single cavity.
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Uniovulate: - With a single ovule.
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Upland: - Used in the descriptions of the altitudinal range of species to indicate altitudes between 300 m and 600 m (Double click to see Montane, Lowland).
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Upright (of crown, leaves, trunk): - Erect, vertical.
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Urceolae / urceolate: - Erect, vertical.
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Valvate: - Two parts that meet exactly and do not overlap.
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Variety: - A subdivision of a species. The term is used mainly for natural variation within a species rather than for new plants produced by cultivation, for which cultivar is more appropriate.
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Vein: - The conducting tissue of leaves.
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Venation: - The arrangement of veins in a leaf.
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Ventricose: - Swollen.
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Verrucae / verrucate: - A wart-like element of ectexine, more than 1 µm wide, broader than it is high and not constricted at the base.
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Versatile: - Of anthers, attached near the centre and movable on the filament.
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Vivipary: - The production of seeds which germinate while still on the parent plant.
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Whip: - A climbing organ in some Calamoideae, general term for cirrus and flagellum.
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Wide-boreal: - A major biome category which includes plants occurring in the Artic-montane, Boreal-montane, and Temperate zones.
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Wide-temperate: - A major biome category which includes plants occurring in the Boreal-montane, Temperate and Southern zones.
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Xerophyte: - A plant adapted to living in very dry conditions.
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Xylem: - The basic tissue of wood, consisting of long cells with thickened walls and responsible for transporting water and mineral salts throughout the tree.
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Zonasulcus / zonasulcate: - A ring-like sulcus. Strictly, 'zonasulcus' equals meridional orientation and 'zonasulculus' equals equatorial orientation. However, the two words are easily confused by the non-specialist and, frequently the terms 'meridional zonasulcus/zonasulcate' or 'equatorial zonasulcus/zonasulcate' are used.
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Zonobiome: - Double click to see biome.