Geonoma macrostachys Information
Identification:
Geonoma macrostachys is the most variable species in the whole genus. Variation is so complex and there is little geographic disjunction. Although G. macrostachys is extremely variable, a number of morphotypes can be distinguished. In the western Amazon region in Colombia, Ecuador, Peru, and Brazil, with an outlying population in southern Peru, there is a morphotype (macrostachys) with usually undivided leaves, non-raised veins, and 1(1-4) pinnae with narrow basal angles of 10(3-40). Specimens from
Amazonas in Peru are particularly variable. Some specimens have wider leaves and almost sigmoid venation and others have unusually large leaves. The type of G. macrostachys is of this morphotype. In the western and central Amazon region in Venezuela, Colombia, Ecuador, Peru, and Brazil there is a morphotype (acaulis) having pinnate leaves, non-raised adaxial veins, 5(3-9) pinnae with wide basal angles of 61(40-90). The types of G. acaulis and G. ecuadoriensis are of the acaulis morphotype. In the western and central Amazon region in Colombia, Ecuador, Peru, Bolivia, and Brazil, with an
outlying population in Bolivia, there is a morphotype (tapajotensis) that is similar to the acaulis morphotype in its pinnate leaves with non-raised veins and 4(2-10) pinnae with wide basal angles of 58(27-100), but has well-developed connectives. The types of G. acaulis subsp. tapajotensis and Taenianthera oligosticha are of this morphotype. In the western Amazon region of Ecuador and adjacent Peru and Colombia there is a morphotype
(atrovirens) with undivided leaves with non-raised veins with narrow basal angles of 7(5-10). In the western Amazon region of Colombia, Ecuador, Peru, and Brazil there is a morphotype (tamandua)
with exceptionally long rachis and undivided leaves with non-raised veins with narrow basal angles of 7(3-17). The leaves are described on labels as dark green, blue green, 'almost black', 'nearly black', or 'dark black-green'. In the western Amazon region of Ecuador and Peru there is a morphotype (supracostata) having undivided or pinnate leaves with raised adaxial veins and 2(1-4) pinnae with wide basal angles of 26(10-48). In the western Amazon region of Ecuador and Peru there is a morphotype (large-raised) with usually divided leaves with raised adaxial veins and 7(1-16) pinnae and narrow basal pinna angles of 10(9-12). In the Peruvian Amazon and adjacent parts of Colombia there is a morphotype (grandiflora) with nonraised adaxial veins, 4(3-7) pinnae per side of the rachis, and wide basal angles of 66(44-90).
Work in progress
Species Information currently being revised!
Distribution:
Native to, Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela
In the western Amazon region at 443(75-1800) m elevation in lowland or montane rainforest.
Location: Brazil (-8.183943°N, -68.203125°E)
Observations
Geonoma macrostachys Overlay Image ©2024 Trebrown - No re-distribution without permission.