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
3.
Geonoma bernalii
Henderson
,
sp. nov.
(Appendix IV, Plate 1)
A speciebus affinibus
prophyllis haud brevibus necnon inaequaliter apiculatis, atque fructibus haud apiculatis crusta haud
tuberculata
differt.
Type:
COLOMBIA
.
Antioquia
: Mun. San Luis,
105 km
al este de Medellín en la carretera a
Bogotá
, vereda Riosol,
1200 m
,
9 October 1987
,
R. Bernal 1399
(
holotype
COL!, isotype NY!).
Plants
1.3 m
tall; stems
1.5 m
tall,
0.5 cm
in diameter, solitary or clustered, cane-like; internodes 1.7(1.0–2.3) cm long, yellowish and smooth.
Leaves
8 per stem, undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 6.3(6.0–6.5) cm long; petioles 5.8(2.0–9.5) cm long, drying green or yellowish; rachis 13.3(12.5–14.1) cm long, 1.6(1.3–1.9) mm in diameter; veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 3 per side of rachis; basal pinna 9.8(9.0–10.5) cm long, 1.4(1.2–1.6) cm wide, forming an angle of 41(37–44)° with the rachis; apical pinna 7.0(6.0–8.0) cm long, 5.2(4.2–6.2) cm wide, forming an angle of 36(33–38)° with the rachis.
Inflorescences
branched 1 order; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, persistent; prophylls 5.3(4.8–5.7) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts
4.5 cm
long, well-developed, inserted
0.6 cm
above the prophyll; peduncles 6.6(6.4–6.7) cm long, 1.5(1.4–1.6) mm in diameter; rachillae 4(3–4), 4.3(4.1–4.4) cm long, 1.3(1.1–1.5) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown with faint to pronounced, short, transverse ridges, filiform with extended narrowed sections between the flower pits; flower pits alternately arranged (sometimes distorted by twisting and contracting of rachillae), 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 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 crenulate or shallowly lobed at the apex, those of non-fertilized flowers not projecting and persistent after anthesis;
fruits
6.0 mm long,
6.2 mm
in diameter, the bases without a prominent, asymmetric stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, not bumpy and not apiculate; locular epidermis without operculum, smooth, without pores.
Distribution and habitat:—
From 6°05’–
6°07’N
and 75°00’–
75°02’W
on the eastern slopes of the Central Cordillera in
Colombia
(
Antioquia
) at 1105(1010–1200) m elevation in montane rainforest (
Fig. 9
).
FIGURE 9
. Distribution maps of
Geonoma aspidiifolia
subsp.
aspidiifolia
,
G
.
aspidiifolia
subsp.
fusca
,
G
.
baculifera
, and
G
.
bernalii
.
Taxonomic notes:—
The two specimens examined have been previously determined as
Geonoma leptospadix
. They bear a superficial resemblance to that species but differ in their alternately arranged flower pits, not hood-shaped proximal lips, and cupular proximal and distal lips.
Geonoma bernalii
is similar to several species in the
G. lanata
clade. It differs from these in its prophylls not short and asymmetrically apiculate, and fruit surfaces not bumpy and not apiculate.
Subspecific variation:—
The only trait to vary between the two specimens examined is stem branching. On both specimens pinnate leaves were measured, but one specimen also has undivided leaves present.