Geonoma longivaginata Wendland ex Spruce (1871: 109)

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 90-91

35. Geonoma longivaginata Wendland ex Spruce (1871: 109) . Type: COSTA RICA. Heredia: Sarapiquí, 1857, H. Wendland s.n. (holotype K!).

Plants 3.0(1.0–8.0) m tall; stems 3.0(1.0–5.0) m tall, 1.1(0.6–2.1) cm in diameter, solitary or clustered, canelike; internodes 3.0(1.2–7.0) cm long, yellowish and smooth. Leaves 9(6–10) per stem, irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 14.9(6.0–26.0) cm long; petioles 28.4(5.5– 58.0) cm long, drying green or yellowish; rachis 52.5(16.5–101.0) cm long, 4.1(1.4–8.0) mm in diameter; veins raised and rectangular in cross-section adaxially or not raised or slightly raised and triangular in crosssection adaxially; pinnae 6(2–13) per side of rachis; basal pinna 23.8(8.5–50.0) cm long, 4.1(0.7–34.5) cm wide, forming an angle of 64(31–92)° with the rachis; apical pinna 16.6(6.7–31.5) cm long, 12.7(5.5–30.0) cm wide, forming an angle of 38(27–50)° with the rachis. Inflorescences branched 1–2 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous; prophylls 9.0(3.3–16.0) cm long, short, asymmetrically apiculate, the margins curved around the stem, the surfaces flat with dense, felty, brown tomentum, prophyll equal to and early deciduous with the peduncular bract, the surfaces not ridged, without unequally wide ridges; peduncular bracts 7.5(4.0–11.6) cm long, well-developed, inserted 0.3(0.1–0.6) cm above the prophyll; peduncles 8.8(3.8–16.0) cm long, 4.9(2.3–9.2) mm in diameter; rachillae 6(2–18), 23.3(10.0–42.0) cm long, 3.2(1.9–5.3) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown, with short, transverse ridges, not filiform and not narrowed between the flower pits; flower pits spirally arranged, 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, 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 onto bifid and well-developed, nonjointed connectives; 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 6.5(5.1–7.9) mm long, 5.3(4.3–6.3) 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.

Taxonomic notes:— Geonoma longivaginata is a member of a group of three species within the G. stricta clade, the other two being G. divisa and G. ferruginea . It differs from G. divisa in its crenulate or shallowly lobed staminodial tube; and from G. ferruginea in its rachillae with short, transverse ridges.

Subspecific variation:— Two traits vary within this species (stem branching, adaxial veins). The species is distributed in Panama and Costa Rica and just reaches Nicaragua. It is divided into several disjunct populations. The state distribution of one trait (adaxial veins) together with geography suggest several subgroups.

Specimens with raised adaxial veins occur in Panama (San Blas) and are treated as a separate subgroup. Specimens with non-raised adaxial veins occur in five areas: Atlantic slope in Costa Rica and adjacent Nicaragua and Panama; Pacific slope in Costa Rica; El Copé, Llano Grande, and Cerro Tife in Panama; El Valle in Panama; and the Santa Rita Ridge in Panama. Specimens from the Atlantic and Pacific slopes in Costa Rica do not differ significantly from each other in any quantitative variable, and these are treated as one subgroup. There are thus five potential subgroups, but there are only three specimens of one of these, from the Santa Rita Ridge in Panama, too few to test for differences. Four potential subgroups are tested for differences.

ANOVA shows that for pair wise comparison probabilities, all variables except leaf number and fruit length differ significantly (P <0.05) between at least one pair of subgroups, although no variable differs amongst all four subgroups. Based on these results and geography, the four subgroups are recognized as subspecies. Specimens from Santa Rita Ridge in Panama are included with those from the Atlantic and Pacific slopes in Costa Rica (see below) (subspp. copensis, longivaginata , sanblasensis, vallensis).

Key to the subspecies of G. longivaginata

1 Veins raised and rectangular in cross-section adaxially; Panama (San Blas) .................................. subsp. sanblasensis - Veins not raised or slightly raised and triangular in cross-section adaxially; Nicaragua, Costa Rica, and Panama..... 2 2 Rachis 67.2(42.0–101.0) cm long; rachillae 7(4–18), 25.7(10.0–42.0) cm long........................... subsp. longivaginata - Rachis 24.9(16.5–37.5) cm long; rachillae 3(2–5), 17.5(14.0–25.2) cm long.............................................................. 3 3 Peduncles 5.2(3.8–7.5) cm long; El Copé, Llano Grande, Cerro Tife................................................... subsp. copensis - Peduncles 9.2(7.4–12.1) cm long; El Valle............................................................................................ subsp. vallensis