Geonoma poiteauana Kunth 1841
Creators: name: Henderson, Andrew
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Arecales
Arecaceae
Geonoma
Geonoma poiteauana

description: 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.
description: Published as part of Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), pp. 1-271 in Phytotaxa 17 on pages 132-133, DOI: 10.11646/phytotaxa.17.1, http://zenodo.org/record/3538362