55. Geonoma schizocarpa Henderson, sp. nov. (Appendix IV, Plates 58 & 59)

A speciebus affinibus crusta fructuum profunde scindens differt.

Type: PERU. Amazonas: al lado de Huampami, 18 July 1974, R. Kyap 1212 (holotype MO!).

Plants 2.2(1.0–5.0) m tall; stem height no data, 2.8 cm in diameter, branching no data, not cane-like; internodes 0.3 cm long, not scaly. Leaves irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 12.0 cm long; petioles drying green or yellowish; rachis 90.0(88.0–92.0) cm long, 7.9(6.2–8.7) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 14 per side of rachis; basal pinna 34.0 cm long, 1.2(0.8–1.6) cm wide, forming an angle of 67(51–82)° with the rachis; apical pinna 20.0 cm long, 4.9(2.8–6.5) cm, forming an angle of 31(30–33)° 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 14.5 cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts length no data, well-developed, inserted 0.6 cm above the prophyll; peduncles 93.0 cm long, 5.7(4.6–7.2) mm in diameter; rachillae 1, 22.6(15.5–36.0) cm long, 9.8(7.7–11.5) 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 flowers persistent post-anthesis or deciduous post-anthesis; staminate and pistillate petals not emergent, not valvate throughout; stamens 6; thecae not diverging at anthesis, inserted onto well-developed, non-split, jointed connectives, alternately long and short; anthers short at anthesis, remaining straight and parallel; nonfertilized 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 14.0(12.3–15.5) mm long, 8.9(8.6–9.3) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces splitting deeply and longitudinally at maturity to reveal mesocarp with dense layer of radial fibers, without fibers emerging, not bumpy, not apiculate; locular epidermis with operculum, smooth, without pores.

Distribution and habitat:— From 4°15’– 4°30’S and 78°10’– 78°30’W in Peru (Amazonas) at 225 m elevation in lowland rainforest (Fig. 37).

Taxonomic notes:— Geonoma schizocarpa is a member of the G. macrostachys clade. Within this it is most closely related to G. macrostachys, G. multisecta, G. paradoxa, and G. poiteauana . It differs from these in its fruits surfaces which split deeply and longitudinally at maturity to reveal mesocarp with a dense layer of radial fibers.

Subspecific variation:— One trait (staminate flower persistence) varies within this species. Two of 10 specimens have deciduous staminate flowers.