A newly described species from Lanyu Island, Taiwan. Pseudostems green, about 2.5 m tall, base not swollen. Leaf blades narrow-oblong, 138-150 cm long, 40 cm wide, rounded and asymmetric at base; petioles 60 cm long, margins erect and basally with wings. Inflorescence subhorizontal, about 46 cm or longer, 1 cm in diameter, densely angled, glabrous, green; spathe green, 27 cm long, 5 cm wide, lanceolate, apex caudate, glabrous; male bracts revolute, persistent, ovate-lanceolate, 6-7 cm long, 3 cm wide, adaxially yellowish-green, lightly pink at their rounded tip, abaxially green. Male flowers 4 per bract in a row, cylindrical, peduncle white, 0.6 cm long, glabrous; compound tepal 2.5 cm long, 1 cm wide, white, 5-lobed, apex of 2 lobes with a short hook-like appendage, inner 3 lobes almost as long as outer lobes or shorter; free tepal membranous, 1.3 cm long, 0.7 cm wide, about half as long as compound petal, boat-shaped, sulcate at outer side, (ovate and cordate at base when pressed), keeled in the central inner side, apex apiculate; stamens 5, anthers white, linear, flat, 1 cm long; filaments white, 1.2 cm long; reduced gynoecium whte, 2.2 cm long; filaments white, 1.2 cm long, not clavate. Fruits 8 per cluster, green, 5.5-7 cm long, 1.5 cm wide, cylindrical, apex bottle-necked, slightly curved, 3-4 angled, glabrous. Seeds numerous, black, irregularly angled, smooth, 0.5 cm in diameter, 0.3 cm thick.
Named after the Yami people who live on Lanyu island in Taiwan. This species is described by the author as being similar to Musa insularimontana. However, the author could not find M. insularimontana in habitat and has not seen it. I have seen M. insularimontana in habitat and I confirm here that this new species is completely dissimilar to M. insularimontana. This new species, M. yamiensis differs in the following ways: Rachis and fruiting pedicel being glabrous not pubescent as in both other Taiwan species. The male bud being a vivid yellow-green colour. And there being only 4 male flowers in 1 single row compared with more than 8 in 2 rows with the other Taiwan species. This is a low elevation banana, M. insularimontana only exists above 300 m. M. yamiensis also possesses slender glabrous fruits, other Taiwan species posses short rounded, pubescent fruits.
Native to, Taiwan
Endemic to Lanyu Island, Taiwan. Only 2 small wild populations in a deep ravine at approx. 50 m alt.