Geonoma simplicifrons Willdenow 1805
Creators: name: Henderson, Andrew
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Arecales
Arecaceae
Geonoma
Geonoma simplicifrons

description: 58. Geonoma simplicifrons Willdenow (1805: 594). Type: VENEZUELA. Caracas, no date, F. Bredemeyer
20 (holotype B n.v., holotype image!).
Geonoma willdenowii Klotzsch (1846: 112). Type: VENEZUELA. Carobobo: near Puerto Cabello, 1846, H. Karsten s.n. (holotype LE n.v., isotypes BM!, G!).
Geomoma fendleriana Spruce (1871: 108). Type: VENEZUELA. Vargas: between Petaquire and the sea, 9 February 1857, A. Fendler 2467 (holotype K!, isotype NY!).
Plants 1.6(0.8–3.0) m tall; stems 1.3(0.5–2.5) m tall, 1.2(0.9–1.4) cm in diameter, solitary, not cane-like or cane-like; internodes 1.0(0.7–1.8) cm long, yellowish and smooth. Leaves undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 10.0(8.0–14.0) cm long; petioles 26.0(13.5–43.0) cm long, drying green or yellowish; rachis 35.4(24.0–45.0) cm long, 3.0(2.2–3.7) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 2(1–4) per side of rachis; basal pinna 29.9(16.0–48.0) cm long, 8.5(2.5–16.5) cm wide, forming an angle of 38(25–45)° with the rachis; apical pinna 19.3(13.0–32.0) cm long, 10.9(6.0–14.3) cm wide, forming an angle of 37(30–43)°. Inflorescences branched 1 order; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened (if tubular, narrow, and elongate then not ribbed), deciduous or persistent; prophylls 14.3(8.2–19.3) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 12.0 cm long, well-developed, inserted 0.9(0.3–2.6) cm above the prophyll; peduncles 18.1(8.0–26.5) cm long, 2.9(1.7–4.6) mm in diameter; rachillae 3(2–5), 14.1(8.0–19.5) cm long, 2.8(2.2–3.8) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown, with faint to pronounced, short, transverse ridges, not filiform and not narrowed between the flower pits; flower pits spirally arranged, densely hairy internally distally only (rarely some hairs on lateral margins of the pit); proximal lips without a central notch before anthesis, not recurved after anthesis, hood-shaped at anthesis, sometimes splitting post-anthesis; 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 absent; 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 or 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 5.9(4.5–6.6) mm long, 4.9(4.3–5.6) 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, sculpted, usually also with a raised, meridional ridge, without pores.
Distribution and habitat:— From 10°04’– 10°37’N and 65°48’– 76°45’W on the Coastal Cordillera in Venezuela at 785(42–1600) m elevation in lowland to montane rainforest (Fig. 37).
Taxonomic notes:— Geonoma simplicifrons is a member of a group of related species, the G. interrupta clade, characterized by its lack of a distal lip of the flower pit and flower pits hairy internally (and not related to G. jussieuana or G. orbignyana, contra Henderson et al., 1995). This group also includes G. euspatha, G. frontinensis, G. interrupta, and G. pinnatifrons. These species have had a checkered taxonomic history but G. simplicifrons has usually been recognized as a distinct species. It differs from G. euspatha, G. frontinensis, and G. pinnatifrons in its flower pits which are densely hairy internally distally only; and from G. interrupta in its prophyll surfaces which are not ridged and without unequally wide ridges.
Subspecific variation:— Only one trait (leaf division) varies within this species. Specimens from the eastern part of the range (east of 67°W) have simple leaves with longer apical pinnae, but simple leaves also occur, rarely, in the western part of the range. Most specimens from the western part of the range have pinnate leaves.
Fred Stauffer (pers. comm.) considers that the maximum height of plants is 1.7 m, and the figure of 3 m is a mistake on the specimen label; that inflorescences are sometimes unbranched (2–5 rachillae reported here); and that the minimum elevation of this subspecies is about 700 m, and that the lower records are mistakes on specimen labels.
description: Published as part of Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), pp. 1-271 in Phytotaxa 17 on pages 139-140, DOI: 10.11646/phytotaxa.17.1, http://zenodo.org/record/3538362