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
40.
Geonoma multisecta
(Burret)
Burret (1940a: 24)
.
Taenianthera multisecta
Burret (1930c: 13)
.
Type
:
COLOMBIA
.
Caquetá
: Sucre,
10 July 1926
,
G
. Woronow &
J
. Juzepczuk 5862
(
holotype
LE
!).
Geonoma polyandra
Skov (1994: 39)
.
Type
:
ECUADOR
.
Napo
: Añangu,
0°32’N
,
76°23’W
,
300 m
,
19 June 1985
,
H.
Balslev, A. Barfod, & F. Skov 60536
(
holotype
AAU!, isotypes COL
n.v.
, K!, NY!, QCA
n.v.
),
s
ynon. nov.
Plants
2.7(1.5–3.5) m tall; stems 0.8(0.2–2.3) m tall, in diameter no data, solitary; internodes length no data, not scaly.
Leaves
11(9–16) per stem, irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 22.0(11.0–38.0) cm long; petioles 41.2(13.0–77.0) cm long, drying green or yellowish; rachis 74.6(55.5–94.0) cm long, 4.3(2.9–8.0) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae13(3–18) per side of rachis; basal pinna 29.0(21.0–54.0) cm long, 2.5(0.2–18.5) cm wide, forming an angle of 56(20–74)° with the rachis; apical pinna 20.6(15.5–29.5) cm long, 5.7(2.0–17.0) cm wide, forming an angle of 32(22–42)° 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 29.1(19.2–40.0) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 29.3(25.0–39.5) cm long, well- developed, inserted 0.8(0.2–2.5) cm above the prophyll; peduncles 60.8(31.0–99.5) cm long, 3.7(2.3–5.1) mm in diameter; rachillae 1, 23.5(14.0–36.5) cm long, 7.4(5.4–9.4) mm in diameter, the surfaces without 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 with a central notch before anthesis, often the two sides of the notch overlapping, 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 more than 6; thecae diverging or not diverging at anthesis, inserted onto poorly to well-developed, non-split, jointed connectives, connectives when well-developed alternately long and short; anthers short at anthesis, remaining straight and parallel; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes lobed at the apex, the lobes spreading at anthesis, acuminate, those of non-fertilized pistillate flowers not projecting and persistent after anthesis;
fruits
11.2(9.6–13.2) mm long, 7.4(6.2–7.9) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, not bumpy, not apiculate; locular epidermis with operculum, smooth, without pores.
Distribution and habitat:—
From
1°47’N–
2°17’S
and 74°53’–
77°45’W
in the western Amazon region of
Colombia
and
Ecuador
at 338(200–1150) m elevation in lowland or) montane rainforest (
Fig. 28
).
FIGURE 28
. Distribution maps of
Geonoma monospatha
,
G
.
mooreana
,
G
.
multisecta
,
and
G
.
occidentalis
.
Taxonomic notes:—
Skov (1994)
, in describing
Geonoma polyandra
, overlooked the earlier name of
G. multisecta
. This was understandable given that the
type
specimen of
G. multisecta
lacked staminate flowers. However, this specimen, with its veins raised and rectangular in cross-section adaxially and leaf and inflorescence morphology certainly represents the earliest name for this species.
Geonoma multisecta
is a member of a group of related species including
G. macrostachys
,
G. paradoxa
,
G. poiteauana
, and
G. schizocarpa
, and is the only one of which to have more than six stamens.
Subspecific variation:—
No trait varies within this species, nor is there any geographic disjunction.