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
54.
Geonoma santanderensis
Galeano & Bernal (2002: 282)
. Type:
COLOMBIA
.
Santander
: Suaita, San José de Suaita, ca.
6°10’N
,
73°27’W
,
1700–1900 m
,
30 July 2001
,
G. Galeano, J. Betancur, N. Castaño, L. Clavijo & N. Garcia 6884
(
holotype
COL!, isotypes HUA
n.v.
, NY
n.v.
, UIS
n.v.
).
Plants
height no data; stems 1.3(1.0–1.5) m tall, 0.8(0.6–0.9) cm in diameter, solitary or clustered, cane-like; internodes 1.5(1.0–2.2) cm long, covered with reddish or brownish scales, especially in their distal part.
Leaves
9(7–12) per stem, irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 8.0(6.0–11.0) cm long; petioles 15.9(8.0–29.0) cm long, drying green or yellowish; rachis 20.5(15.5– 25.0) cm long, 1.6(1.4–2.2) mm in diameter; veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 5(3–6) per side of rachis; basal pinna 10.7(9.7–11.5) cm long, 1.1(0.8–1.8) cm wide, forming an angle of 60(45–72)° with the rachis; apical pinna 8.2(7.0–10.0) cm, 7.5(6.3–11.0) cm wide, forming an angle of 42(38–48)° with the rachis.
Inflorescences
unbranched; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous or persistent; prophylls 8.5(6.7–11.2) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 7.3(5.9–10.5) cm long, well-developed, inserted 1.1(0.5–2.3) cm above the prophyll; peduncles 8.7(6.0–14.5) cm long, 2.1(1.5–2.8) mm in diameter; rachillae 1, 8.4(5.7–10.0) cm long, 3.4(2.6– 4.1) mm in diameter, the surfaces with 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 usually 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, 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 onto bifid and well-developed, non-jointed connectives; 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 non-fertilized pistillate flowers not projecting and persistent after anthesis;
fruits
8.5(7.8–9.9) mm long, 6.0(4.6–7.2) 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 6°10’–
7°08’N
and 72°54’–
73°27’W
in the Eastern Cordillera in
Colombia
at
1800 m
elevation in montane rainforest (
Fig. 36
).
Taxonomic notes:—
Geonoma santanderensis
was compared to
G. monospatha
by
Galeano and Bernal (2002)
. However, it appears closely related to a group of species within the
G. stricta
clade comprising
G. aspidiifolia
and
G. oligoclona
. All three species share internodes covered with reddish or brownish scales, especially in their distal part, rachillae surfaces with spiky, fibrous projections or ridges, and staminodial tubes lobed at the apex with the lobes not spreading at anthesis and not acuminate.
Geonoma santanderensis
differs from
G. aspidiifolia
in its fruits which are bumpy from the numerous, subepidermal, tangential, short fibers present; and from
G. oligoclona
in its prophyll which is not short and asymmetrically apiculate.
Subspecific variation:—
No traits, except for stem branching, vary within this species. The specimens come from two separate areas, but there are too few specimens to test for differences between these.