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
53.
Geonoma sanmartinensis
Henderson
,
sp. nov.
(Appendix IV, Plate 57)
A speciebus affinibus
crusta fructuum fibris epidermalibus brevibus numerosis apicem convergentibus differt.
Type:
PERU
.
San Martín
: Prov. Rioja, Dist. Naranjillo, sector San Augustin, Bosque de Protección de Alto Mayo,
5°48’S
,
77°21’W
,
1250 m
,
13 November 1996
,
I. Sánchez Vega & M. Dillon 8658
(
holotype
NY!, isotypes CPUN
n.v.
, F!).
Plants
1.2(0.5–2.0) m tall; stem branching no data; stem
type
no data; stem height no data; stem diameter no data; internode color no data; internode length no data.
Leaves
irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths no data; petioles drying green or yellowish; rachis 38.6(35.8–41.0) cm long, 3.2(2.3–4.0) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 4(3–7) per side of rachis; basal pinna 28.1(27.0–29.5) cm long, 4.3(0.9–6.8) cm wide, forming an angle of 46(30– 60)° with the rachis; apical pinna length no data, 12.3(9.2–15.0) cm wide, forming an angle of 27(22–32)° with the rachis.
Inflorescences
unbranched; prophylls and peduncular bracts ribbed with elongate, unbranched fibers, both bracts tubular, narrow, elongate, closely sheathing the peduncle, more or less persistent; prophylls 12.6(11.0–14.2) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 23.0(16.0–30.0) cm long, well-developed; inserted 1.1(0.8–1.4) cm above the prophyll; peduncles 63.5(63.0–64.0) cm long, 2.9(2.6–3.1) mm in diameter; rachillae 1, 21.1(18.5–24.7) cm long, 3.6(3.1–3.9) 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 spirally arranged, glabrous internally; proximal lips without a central notch before anthesis, not recurved after anthesis, hood-shaped at anthesis, sometimes splitting post-anthesis; 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 a scarcely raised rim; 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, smooth, without pores.
Distribution and habitat:—
From 5°45’–
5°54’S
and 77°21’–
77°45’W
in Andean regions of
Peru
(
San Martín
) at 1525(1250–1850) m elevation in montane rainforest (
Fig. 36
).
Taxonomic notes:—
Geonoma sanmartinensis
appears most similar to
G. brongniartii
. It differs in its fruits which are bumpy from the numerous, subepidermal, tangential, short fibers present.
Subspecific variation:—
No trait varies within this species, nor is there any geographic disjunction.