A revision of Geonoma (Arecaceae)
Author
Henderson, Andrew
text
Phytotaxa
2011
2011-02-18
17
1
271
journal article
24911
10.11646/phytotaxa.17.1
65962ba7-eec1-40e7-aed6-cef94e99ca39
1179-3163
3538362
28.
Geonoma hugonis
Grayum & de Nevers in
de Nevers & Grayum (1998: 94)
.
Type:
PANAMA
.
Chiriquí
: Fortuna Dam Area, between Quebrada Los Chorros and Quebrada Hondo, to
N
of reservoir, in forest
N
of road,
8°45’N
,
82°14’W
,
1100 m
,
20 September 1984
,
H
. Churchill &
A
. Churchill 6185
(
holotype
MO
!, isotype
CAS
,
n.v.
).
Plants
0.8(0.3–1.5) m tall; stems 0.7(0.1–1.2) m tall, 0.6(0.4–0.8) cm in diameter, solitary or clustered, canelike; internodes 1.9(1.0–3.5) cm long, covered with reddish or brownish scales, especially in their distal part.
Leaves
8(4–12) per stem, undivided, not plicate, bases of blades running diagonally into the rachis; sheaths 7.2(3.5–14.0) cm long; petioles 7.0(1.0–12.0) cm long, drying green or yellowish; rachis 12.7(7.0–20.0) cm long, 1.8(1.3–2.7) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 1 per side of rachis; basal pinna length and width not applicable, forming an angle of 29(22–40)° with the rachis; apical pinna 10.4(5.8–17.2) cm long, width not applicable, forming an angle of 32(22–42)° 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 12.8(11.0– 17.0) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 11.4(1.5–18.4) cm long, well-developed, inserted 20.4(17.8–23.0) cm above the prophyll; peduncles 29.9(13.5–43.5) cm long, 1.3(0.9–2.0) mm in diameter; rachillae1, 7.1(4.6–12.5) cm long, 2.4(1.7– 3.5) 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, not recurved after anthesis, not hood-shaped at 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 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 deciduous after anthesis; staminodial tubes lobed, the lobes not spreading at anthesis, not acuminate; staminodial tubes of non-fertilized pistillate flowers not projecting and persistent after anthesis;
fruits
6.2(5.4–6.9) mm long, 5.4(4.7–6.3) 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.
Distribution and habitat:—
From 8°30’–
8°46’N
and 81°45’–
82°17’W
in western
Panama
at 1243(1100–1450) m elevation in montane rainforest (
Fig. 20
).
FIGURE 20
. Distribution maps of
Geonoma hollinensis
and
G
.
hugonis
.
Taxonomic notes:—
Geonoma hugonis
is a member of a group of four Central American species, part of the
G. cuneata
clade, also including
G. brenesii
,
G. monospatha
,
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 hugonis
differs from these species in its internodes covered with reddish or brownish scales.
Subspecific variation:—
Only one trait (stem branching) varies in this species. There is geographic disjunction but this is likely to be an artifact of insufficient collecting.