Geonoma operculata Henderson, 2011

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 108-110

44. Geonoma operculata Henderson , sp. nov. (Appendix IV, Plate 52)

A speciebus affinibus operculo differt.

Type: VENEZUELA. Miranda: Cordillera de la Costa, al noreste de Guatire, Fila Juan Torres-Fila Las Perdices, por el río Guayabal hacia el pueblo Guayabal, 10°31’N, 66°20’W, 700–900 m, 19–22 February 1993, W. Meier 3401 (holotype NY!, isotype VEN n.v.).

Plants 2.0 m tall; stems height and in diameter no data; internodes yellowish and smooth. Leaves irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths no data; petioles drying green or yellowish; rachis 23.0 cm long; veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 3 per side of rachis; basal pinna length, width and angle no data; apical pinna 12.5 cm long, 9.0 cm wide, forming an angle of 34° with the rachis. Inflorescences branched 2 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous or persistent; prophylls length 4 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 no data; peduncles 12.0 cm long, 3.2 mm in diameter; rachillae 37, 15.0 cm long, 0.8 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), 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 no data; staminodial tubes crenulate or shallowly lobed at the apex, persistence no data; fruits 7.5 mm long, 5.8 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 with operculum, smooth, without pores.

Distribution and habitat:— At 10°31’N and 66°20’W in the Coastal Cordillera in Venezuela (Miranda) at 800 m elevation in lowland rainforest ( Fig. 29 ).

Taxonomic notes:— This species is based on a single specimen. This is very similar to specimens of G. braunii , and in fact it was identified as such by Stauffer (1997, as G. spinescens var. braunii ). However, the fruits of the specimen (in a separate packet, see Appendix IV, Plate 52) have an operculum, and because of this the specimen is here recognized as a separate species. It is the only species outside of the Geonoma congesta clade to have fruits with an operculum. Apart from the operculum, the specimen bears no resemblance to species in the G. congesta clade but appears similar to specimens of G. braunii .

Subspecific variation:— No trait varies within this species and only one specimen is known.

Figures

FIGURE 29. Distribution maps of Geonoma oldemanii, G. oligoclona, G. operculata, and G. orbignyana subsp. orbignyana.