Geonoma brenesii Grayum (1998: 322)

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 41-42

5. Geonoma brenesii Grayum (1998: 322) . Type: COSTA RICA. Alajuela: Reserva Biológica de San Ramón, road from Las Lagunas to Colonia Palmareña, 10°04’N, 84°32’W, 850–1100 m, 30 May 1986, G. de Nevers, B. Hammel & C. Gómez 7789 (holotype MO!, isotypes CR!, NY!).

Plants 0.8(0.5–1.0) m tall; stems 0.3(0.2–0.4) m tall, 1.2 cm in diameter, solitary, not cane-like; internodes 0.5 cm long, not scaly. Leaves 9(8–11) per stem, irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 8.2(6.5–10.0) cm long; petioles 31.8(21.0–38.5) cm long, drying green or yellowish; rachis 24.6(18.8–29.8) cm long, 2.8(1.9–4.3) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 3(3–4) per side of rachis; basal pinna 28.3(21.5–36.5) cm long, 4.1(2.0–10.2) cm wide, forming an angle of 43(30–53)° with the rachis; apical pinna 16.7(13.5–21.0) cm long, 9.5(6.5– 12.0) cm wide, forming an angle of 29(25–32)° 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 13.5(10.0–17.5) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 3.9(1.5– 7.1) cm long, vestigial, inserted 4.9(3.4–7.0) cm above the prophyll; peduncles 24.3(15.0–37.5) cm long, 2.1(1.4–2.8) mm in diameter; rachillae 1, 12.5(8.5–16.0) cm long, 3.6(2.8–5.0) 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, the lip, more or less heart–shaped, 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 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 persistent after anthesis; staminodial tubes lobed, the lobes not spreading at anthesis, not acuminate, those of non-fertilized flowers not projecting and persistent after anthesis; fruits 7.3(6.9–7.6) mm long, 6.1(6.0–6.2) 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 10°02’– 10°23’N and 83°59’– 84°51’W in Costa Rica at 1293(967– 1550) m elevation in montane rainforest ( Fig. 10 ).

Taxonomic notes:— Geonoma brenesii is a member of a group of four Central American species, part of the G. cuneata clade, including G. monospatha , G. hugonis , and G. epetiolata . They all have unbranched or few-branched inflorescences and share the character state of the staminodial tubes being lobed at the apex, but the lobes are not spreading at anthesis and are not acuminate. Geonoma brenesii is most similar to G. monospatha , differing in its tubular, narrow, elongate, sheathing, persistent prophylls and peduncular bracts which are ribbed with unbranched fibers.

Subspecific variation:— No traits vary within this species.

Figures

FIGURE 10. Distribution maps of Geonoma braunii, G. brenesii, G. brongniartii subsp. brongniartii, and G. brongniartii subsp. pascoensis.