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
23.
Geonoma fosteri
Henderson
,
sp. nov.
(Appendix IV, Plate 34)
A speciebus affinibus
prophyllis brevibus inaequaliter apiculatis atque rachide breviore, crusta fructuum fibris subepidermalibus brevibus numerosis apicem convergentibus
tuberculata
, operculo carens differt.
Type:
ECUADOR
.
Sucumbios
: Sinangoe Station, Shishicho Ridge, Alto Aguarico drainage, above (south of) Río Cofanes, west of Puerto Libre, NW of Lumbaqui,
00°12’N
,
77°31’ W
,
1300–1450 m
,
14 August 2001
,
R. Aguinda, N. Pitman & R. Foster 1315
(
holotype
F!, isotype QCNE,
n.v.
).
Plants
height no data; stems
1.5 m
tall,
0.7 cm
in diameter, cane-like; internodes 1.0 cm long, yellowish and smooth.
Leaves
irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths
6.5 cm
long; petioles 11.0 cm long, drying green or yellowish; rachis
20.5 cm
long, 3.1(2.1–4.1) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 3 per side of rachis; basal pinna
19.5 cm
long,
1.5 cm
wide, forming an angle of 63(58–68)° with the rachis; apical pinna
16.5 cm
long,
8.5 cm
wide, forming an angle 28° with the rachis.
Inflorescences
branched 3 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers; prophylls
5.2 cm
long, short, asymmetrically apiculate, the margins curved around the stem, the surfaces flat with dense, felty, brown tomentum, prophyll equal to and early deciduous with the peduncular bract, the surfaces not ridged, without unequally wide ridges; peduncular bracts no data, inserted
0.4 cm
above the prophyll; peduncles
5.7 cm
long, 3.4(2.9–3.8) mm in diameter; rachillae
10.5 cm
long, 1.0(0.9–1.1) 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 pistillate flowers not projecting and persistent after anthesis;
fruits
size no data, 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.
Distribution and habitat:—
From 0°12’–
0°19’N
and 77°25’–
77°31’W
on eastern Andean slopes in
Ecuador
at 1592(
1375–1810
) m elevation in montane rainforest (
Fig. 19
).
Taxonomic notes:—
Geonoma fosteri
is similar to a group of species within the
G. lanata
clade. It differs from
G. bernalii
,
G. dindoensis
,
G. lanata
,
and
G. venosa
in having short, asymmetrically apiculate prophylls with the margins curved around the stem and the surfaces flat with dense, felty, brown tomentum; from
G. tenuissima
in its fruit surfaces bumpy from the numerous, subepidermal, tangential, short fibers present; and from
G. operculata
by its locular epidermis without an operculum. Only two specimens are known. These share the same character states as
G. braunii
, but the peduncular bract is unknown in
G. fosteri
. Given the large geographic distance between the two, they are kept separate pending more complete material.
Subspecific variation:—
No trait varies within this species.