Geonoma poiteauana Kunth (1841: 233)

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 132-133

52. Geonoma poiteauana Kunth (1841: 233) . Gynestum acaule Poiteau (1822: 391) . Geonoma poiteana

Martius (1843: 39). Geonoma acaulis (Poiteau) Burret (1930a: 162) . Geonoma macrostachys var. poiteauana

(Kunth) Henderson (1995: 277). Type: FRENCH GUIANA. Without locality, no date, A. Poiteau s.n.

(holotype P!).

Geonoma dammeri Huber (1902: 409) . Taenianthera dammeri (Huber) Burret (1930c: 13) . Type: BRAZIL. Pará: Furo Macujubim, 6 October 1901, M. Guedes 2241 (holotype MG!).

Geonoma chaunostachys Burret (1931c: 318) . Type: VENEZUELA. Amazonas: Mount Duida, ca. 250 m, 18 November 1928, G. Tate 394 (holotype NY!).

Plants 1.2(0.5–2.0) m tall; stems 0.1 m tall, 2.1 cm in diameter, branching no data, not cane-like; internodes 0.2 cm long, not scaly. Leaves undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 13.7(12.0–17.0) cm long; petioles 21.6(18.0–26.7) cm long, drying green or yellowish; rachis 57.0(38.0–79.5) cm long, 4.2(3.1–5.9) mm in diameter; adaxial veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 2(1–3) per side of rachis; basal pinna 51.8(42.0–64.0) cm long, 16.6(9.0–26.0) cm wide, forming an angle of 11(5–22)° with the rachis; apical pinna 33.4(30.0–38.0) cm long, 16.9(9.5–31.5) cm wide, forming an angle of 18(10–24)° with the rachis. Inflorescences unbranched; prophylls and peduncular bracts ribbed with elongate, unbranched fibers, both bracts tubular, narrow, elongate, closely sheathing the peduncle, more or less persistent; prophylls 10.4(6.0–13.2) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 23.4(19.0–28.35) cm long, well-developed, inserted 0.9(0.5–2.0) cm above the prophyll; peduncles 80.2(54.5–119.5) cm long, 2.9(1.3–3.7) mm in diameter; rachillae 1, 13.2(8.5–20.0) cm long, 4.8(3.1–6.0) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown or yellow-brown, without short, transverse ridges, not filiform and not narrowed between the flower pits; flower pits spirally arranged, glabrous internally; proximal lips with a central notch before anthesis, often the two sides of the notch overlapping, not recurved after anthesis, not hood-shaped; proximal and distal lips drying the same color as the rachillae, not joined to form a raised cupule, the proximal lip margins overlapping the distal lip margins; distal lips well-developed; staminate and pistillate petals not emergent, not valvate throughout; staminate flowers deciduous after anthesis; stamens 6; thecae diverging or not diverging at anthesis, inserted onto well-developed, non-split, jointed connectives, connectives alternately long and short; anthers short at anthesis, remaining straight and parallel; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes lobed at the apex, the lobes spreading at anthesis, acuminate, those of non-fertilized pistillate flowers not projecting and persistent after anthesis; fruits 8.8(7.9–9.5) mm long, 7.2(6.4–8.0) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, not bumpy, not apiculate; locular epidermis with operculum, smooth, with pores.

Distribution and habitat:— From 7°45’N– 8°00’S and 47°10’– 70°11’W in the eastern and central Amazon region of the Guianas, Venezuela, Colombia, and Brazil, at 242(1–725) m elevation in lowland rainforest ( Fig. 36 ).

Taxonomic notes:— Geonoma poiteauana was recognized by Henderson (1995) as a variety of Geonoma macrostachys , but is here recognized at the species level. The two are closely related, G. poiteauana differing by its fruits which are not bumpy and not apiculate. It belongs to a group of species within the G. macrostachys clade, comprising G. macrostachys , G. multisecta , G. paradoxa , and G. schizocarpa .

Subspecific variation:— Only one trait (leaf division) varies within this species.

Figures

FIGURE 36. Distribution maps of Geonoma pohliana subsp. wittigiana, G. poiteauana, G. sanmartinensis, and G. santanderensis.