Geonoma aspidiifolia Spruce (1871: 112)

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 36-37

1. Geonoma aspidiifolia Spruce (1871: 112) . Type: BRAZIL. Amazonas: Tarumã, February 1855, R. Spruce 75 (holotype K!, isotype NY!).

Plants 1.8(1.0–3.0) m tall; stems 1.8(1.0–3.0) m tall, 0.8(0.5–1.6) cm in diameter, solitary or clustered, canelike; internodes 2.7(1.1–7.8) cm long, covered with reddish or brownish scales, especially in their distal part. Leaves 9(6–12) per stem, irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 9.5(8.5–11.5) cm long; petioles 20.6(8.0–29.0) cm long, drying green or yellowish; rachis 19.5(12.0– 38.0) cm long, 2.3(1.3–3.5) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 3(2–4) per side of rachis; basal pinna 13.7(8.2–25.3) cm long, 1.5(0.5–3.8) cm wide, forming an angle of 74(45–90)° with the rachis; apical pinna 13.9(9.0–19.8) cm long, 8.7(4.5–13.8) cm wide, forming an angle of 35(25–43)° with the rachis. Inflorescences branched 1 order; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, persistent; prophylls 5.7(3.5–8.8) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 4.9(3.2– 8.2) cm long, well-developed, inserted 0.5(0.2–0.8) cm above the prophyll; peduncles 5.1(3.4–8.2) cm long, 3.5(2.2–4.8) mm in diameter; rachillae 3(2–4), 7.3(4.0–16.0) cm long, 3.4(2.3–4.9) mm in diameter, the surfaces with 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 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, non-jointed connectives; anthers short and curled over at anthesis; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes lobed at the apex, the lobes not spreading at anthesis, not acuminate, those of non-fertilized flowers not projecting and persistent after anthesis; fruits 9.5(7.9–11.2) mm long, 6.7(6.0–7.8) 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 without operculum, smooth, without pores.

Taxonomic notes:— Geonoma aspidiifolia is a member of the G. stricta clade and is closely related to two other species— G. oligoclona and G. santanderensis . It differs from these two in its fruits surfaces which are not bumpy. Wessels Boer (1968) misunderstood G. aspidiifolia , as shown by Henderson (1995). However, both Henderson (1995) and Henderson et al. (1995) included G. fusca as a synonym of G. aspidiifolia . As explained below, the two are here recognized at the subspecific level.

Subspecific variation:— One trait (stem branching) varies within this species. There is geographic discontinuity and two subgroups can be recognized—Guyana, and the central Amazon region in Brazil. Specimens from Guyana differ significantly from Brazilian specimens in eight variables (stem diameter, rachis length, basal pinna length, prophyll length, peduncular bract length, peduncle length, peduncle width, and fruit diameter)(t -test, P <0.05). Based on these results, and geographic discontinuity, the two subgroups are recognized as subspecies (subspp. aspidiifolia , fusca ).

Key to the subspecies of G. aspidiifolia

1 Peduncles 4.3(3.4–6.0) cm long; peduncular bracts 4.0(3.2–4.7) cm long; central Amazon region of Brazil.............. ........................................................................................................................................................... subsp. aspidiifolia

- Peduncles 6.1(4.5–8.2) cm long; peduncular bracts 6.6(4.5–8.2) cm long; Guyana.................................. subsp. fusca