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
59.
Geonoma spinescens
Wendland ex
Burret (1930a: 230)
. Type:
VENEZUELA
. “Nueva Grenada”, no date,
L. Schlim s.n.
(
holotype
B, destroyed).
Lectotype
(designated by
Stauffer 1997
):
Dahlgren (1959)
, plate 286.
Geonoma tenuis
Burret (1937a: 478)
. Type:
VENEZUELA
.
Aragua
: Rancho Grande,
1200 m
,
8 January 1937
,
H. Pittier 13840
(
holotype
B, destroyed, isotypes F!, VEN
n.v.
).
Plants
1.0 m tall; stems 0.5(0.3–0.75) m tall, in diameter no data, solitary; internodes length no data, yellowish and smooth.
Leaves
undivided, not plicate, bases of blades running diagonally into the rachis; sheaths 18.0 cm long; petioles 26.3(15.0–40.0) cm long, drying green or yellowish; rachis 37.3(33.5–40.5) cm long, 3.6(3.0–3.9) 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 25(17–31)° with the rachis; apical pinna 22.4(18.5–25.8) cm long, width not applicable, forming an angle of 30(28–30)°.
Inflorescences
branched 1–2 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous or persistent; prophylls no data; peduncular bracts length no data, well-developed, inserted
0.4 cm
above the prophyll; peduncles 28.5(27.5–29.5) cm long, 2.9(2.5–3.4) mm in diameter; rachillae 17(9–31), 11.6(9.5–14.4) cm long, 1.2(1.0–1.5) 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, 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 welldeveloped; 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 crenulate or shallowly lobed at the apex, those of nonfertilized pistillate flowers not projecting and persistent after anthesis;
fruits
7.1 mm
long,
5.5 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 10°20’–
10°24’N
and 67°41’–
67°57’W
in the Coastal Cordillera in
Venezuela
(
Aragua
,
Carabobo
) at 1075(800–1330) m elevation in lowland or montane rainforest (
Fig. 38
).
Taxonomic notes:—
Geonoma spinescens
is a member of a relatively large group of similar species, the
G. lanata
clade. It differs from all of these, except
G. gentryi
, in its spirally arranged flower pits. See notes under
G. gentryi
for further discussion.
Subspecific variation:—
No trait varies within this species. According to
Stauffer (1997)
the leaves are rarely irregularly pinnate with multi-veined pinnae. This species is scored as having the flower pits spirally arranged, but some specimens, especially those from
Carabobo
, have almost distichously arranged flower pits.