Geonoma undata subsp. appuniana (Spruce) Henderson, 2011

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 158

67b. Geonoma undata subsp. appuniana (Spruce) Henderson , comb. & stat. nov

Basionym: Geonoma appuniana Spruce (1871: 106) . Type: GUYANA. Cuyuni-Mazaruni: Mount Roraima, 1864, C. Appun 1141 (holotype K!).

Geonoma roraimae Dammer (1915: 261) . Type: GUYANA. Cuyuni-Mazaruni: Mount Roraima, 1800–2300 m, February 1910, E. Ule 8805 (holotype B, destroyed, isotypes K!, L!, US!).

Leaves veins raised and rectangular in cross-section adaxially; basal pinna 3.8(0.5–27.0) cm wide; apical pinna 6.4(1.5–15.0) cm wide. Inflorescences prophyll margins with irregular, spine-like projections; flower pits usually spirally arranged, not distantly spaced.

Distribution and habitat:— From 0°46’– 6°04’N and 59°50’– 66°04’W in the Guayana Highland region of Venezuela, Brazil, and Guyana at 1752(810–2700) m elevation in montane rainforest ( Fig. 42 ).

There is geographic discontinuity and specimens occur on many, isolated mountains, but there are too few specimens from each mountain to test for differences amongst them.

There is geographical variation in this subspecies. Linear regression shows there are significant associations between elevation and three leaf and four inflorescence variables. Squared multiple R for the regression of rachis width on elevation is 0.40, basal pinna angle 0.29, apical pinna angle 0.58, prophyll length 0.23, rachilla width 0.23, fruit length 0.49, and fruit diameter 0.45. The rachis becomes thicker, pinna angles narrower, prophylls longer, rachillae thicker, and fruits longer and wider with increasing elevation.

Figures

FIGURE 42. Distribution maps of Geonoma undata subsp. undata, G. undata subsp. appunniana, G. undata subsp. dussiana, and G. undata subsp. edulis.