Geonoma venosa Henderson, 2011

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 162

68. Geonoma venosa Henderson , sp. nov. (Appendix IV, Plate 72)

A speciebus affinibus venis prominentibus atque rachillis tenuibus differt.

Type: ECUADOR. Imbabura: Cotacachi, Parroquia García Moreno, Reserva Biológica Los Cedros, 0°19’N, 78°46’W, 1470 m, 25 October 2005, H. Vargas, W. Defas & D. Reyes 6282 (holotype NY!, isotype MO n.v.).

Plants 2.5(2.0–3.0) m tall; stems no data; internodes no data. Leaves undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths no data; petioles 13.5 cm long, drying green or yellowish; rachis 27.5 cm long, 2.8(2.0–3.6) mm in diameter; veins raised and rectangular in crosssection adaxially; pinnae 1–? per side of rachis; basal pinna length no data, 14.7 cm wide, forming an angle of 38(35–40)° with the rachis; apical pinna 24.5 cm long, 12.3 cm wide, forming an angle of 30(29–30)° with the rachis. Inflorescences branched at least 3 orders; prophylls and peduncular bracts no data; peduncles no data; rachillae 8.6(7.0–10.2) cm long, 0.9(0.8–0.9) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown, with faint to pronounced, short, transverse ridges, filiform with extended narrowed sections between the flower pits; flower pits alternately arranged (sometimes distorted by twisting and contracting of rachillae), sometimes decussately, then the groups not consistently arranged throughout the rachillae, glabrous internally; proximal lips without a central notch before anthesis, not recurved after anthesis, not hood-shaped; proximal and distal lips drying the same color as the rachillae, joined to form a raised cupule, the margins not overlapping; distal lips well-developed; staminate and pistillate petals not emergent, not valvate throughout; staminate flowers deciduous after anthesis; stamens 6; thecae diverging at anthesis, inserted almost directly onto the filament apices, the connectives bifid but scarcely developed; anthers short and curled over at anthesis; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes crenulate or shallowly lobed at the apex, those of non-fertilized pistillate flowers not projecting and persistent after anthesis; fruits 8.1 mm long, 7.2 mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, bumpy from the numerous, subepidermal, tangential, short fibers present, these coming to a point at fruit apices; locular epidermis without operculum, smooth, without pores.

Distribution and habitat:— From 0°18’– 0°19’N and 78°46’– 78°47’W on western Andean slopes in Ecuador (Reserva Biológica Los Cedros) at 1465(1460–1470) m elevation in montane rainforest ( Fig. 44 ).

Taxonomic notes:— Geonoma venosa is a member of a group of closely related species, the G. lanata clade. It shares all character states with G. tenuissima , but the only two specimens known are missing prophylls and peduncular bracts, so that five characters cannot be scored. Given its larger fruits (8.1 mm long and 7.2 mm in diameter versus 5.3(4.6–6.0) cm long and 4.8(4.1–5.5) mm in diameter), veins raised and rectangular in cross-section adaxially (versus not raised), and higher elevation habitat (1465(1460–1470) m versus 597(520–700) m elevation) it is kept separate from G. tenuissima , pending more material.

Subspecific variation:— No traits vary within species, nor is there any geographic discontinuity.

Figures

FIGURE 44. Distribution maps of Geonoma undata subsp. tumucensis, G. undata subsp. venezuelana and G. venosa.