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
27.
Geonoma hollinensis
Henderson, Borchsenius & Balslev (2008: 195)
. Type:
ECUADOR
.
Napo
: Hollin- Loreto road to Coca
27 km
from take-off from Baeza-Tena road,
0°42’S
77°40’W
,
1000–1100 m
,
28 September 1995
,
H. Balslev 6418
(
holotype
AAU!, isotype QCA,
n.v.
).
Plants
2.3(2.0–3.0) m tall; stems 1.9(1.5–2.2) m tall, 0.8(0.7–0.8) cm in diameter, clustered, cane-like; internodes 0.6(0.5–0.8) cm long, yellowish and smooth.
Leaves
6(6–7) per stem, undivided, not plicate, bases of blades running diagonally into the rachis; sheaths 9.3(8.5–10.5) cm long; petioles 8.8(6.0–12.5) cm long, drying green or yellowish; rachis 25.0(23.5–26.7) cm long, 2.9(2.4–3.4) mm in diameter; veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 1 per side of rachis; basal pinna length and width not applicable, forming an angle of 31(26–38)° with the rachis; apical pinna 16.8(14.5–19.5) cm long, forming an angle of 27(22–30)° with the rachis.
Inflorescences
branched 2 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous or persistent; prophylls 10.0(9.9– 10.0) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts
2.5 cm
long, vestigial, inserted 2.2(0.9–3.4) cm above the prophyll; peduncles 11.1(9.5– 12.7) cm long, 2.3(1.8–2.6) mm in diameter; rachillae 29(23–34), 8.5(8.2–8.8) cm long, 1.6(1.3–2.3) 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 tricussately arranged throughout the rachillae, the groups of pits closely spaced, glabrous internally; proximal lips without a central notch before anthesis, not recurved after anthesis, hood-shaped at anthesis, sometimes splitting postanthesis; 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 3; thecae diverging at anthesis, inserted almost directly onto the filament apices, the connectives bifid but scarcely developed; anthers short and curled over at anthesis; staminodial tubes crenulate or shallowly lobed at the apex, those of non-fertilized pistillate flowers not projecting, deciduous after anthesis;
fruits
6.8 mm
long, 5.0 mm in diameter, the bases without a prominent stipe, the apices not ovoid and conical apices, 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 0°42’–
0°52’S
and 77°26’–
77°40’W
in
Ecuador
at 1125(1050–1200) m elevation in montane rainforest on eastern Andean slopes (
Fig. 20
).
Taxonomic notes:—
Geonoma hollinensis
is one of only two species of
Geonoma
with staminate flowers with three stamens;
G. triandra
is the other. Lacking staminate flowers, it can also be recognized by its vestigial peduncular bracts and tricussately arranged flower pits.
Subspecific variation:—
There is no variation in any trait amongst the four specimens known.