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
14a.
Geonoma cuneata
subsp.
cuneata
(Plates V & VI)
Geonoma obovata
Wendland ex
Spruce (1871: 104)
. Type:
COSTA RICA
.
Heredia
: Sarapiquí, near Pedregal,
August 1857
,
H. Wendland s. n.
(
holotype
K!).
Geonoma gracilis
Wendland ex
Spruce (1871: 105)
.
Geonoma cuneata
var.
gracilis
(Wendland ex Spruce) Skov ex
Govaerts & Dransfield (2005: 114)
. Type:
COSTA RICA
.
Heredia
: Sarapiquí,
August 1857
,
H. Wendland s.n.
(
holotype
K!).
Geonoma cuneatoidea
Burret (1930a: 167)
. Type:
COLOMBIA
.
Antioquia
: Murrí, ca.
1000 m
,
21 July 1880
,
W. Kalbreyer 1828
(
holotype
B, destroyed).
Neotype
(selected by
Bernal
et al.
1989
):
COLOMBIA
.
Antioquia
: Mun. Frontino, Corregimiento de Murrí, La Blanquita,
815 m
,
22 March 1982
,
R. Bernal & G. Galeano 286
(
neotype
COL!).
Leaves
undivided or pinnate; petioles drying green or yellowish; veins raised and rectangular in cross-section adaxially; rachis 45.1(12.0–250.0) cm long; pinnae 3(1–35) per side of rachis.
Inflorescences
staminate flowers deciduous after anthesis; non-fertilized pistillate flowers deciduous after anthesis.
Distribution and habitat:—
From
12°18’N–
1°48’S
and 71°20’–
85°23’W
in
Nicaragua
,
Costa Rica
,
Panama
,
Colombia
,
Venezuela
, and
Ecuador
at 541(2–1750) m elevation in lowland or montane rainforest (
Fig. 13
).
Geonoma cuneata
subsp.
cuneata
is made up of a series of slightly differing morphotypes. There are a few specimens that do not fit into any of these morphotypes. These are usually single specimens from isolated areas.
Specimens from the Atlantic slope in
Costa Rica
(
atlantic
morphotype), a few specimens just reaching the Pacific slope, and a few from adjacent
Panama
have undivided or pinnate leaves with raised adaxial veins. When pinnate, the apical pinna is usually wide. The
types
of
G. cuneata
,
G. gracilis
, and
G. obovata
come from this area. Regression shows there are significant associations between elevation and three leaf variables. Squared multiple
R
for the regression of rachis length on elevation is 0.32, basal pinna angle 0.38, and apical pinna angle 0.40. Specimens from higher elevations tend to have shorter rachis and wider basal and apical angles.
There are two unplaced specimens from this region. In
Nicaragua
there is a single specimen (
Nee 28420
) from cloud forest in
Chontales
. To the south of this, at a lower elevation, is another single specimen (
Stevens 8967
), with a undivided leaf with a narrow basal angle. Both these are separated from other Atlantic slope specimens in
Costa Rica
by a large population of
subsp.
procumbens
.
On the Pacific slope (
pacific
morphotype), specimens occur only in
Costa Rica
, and are concentrated in the Osa Peninsula region. They are similar to Atlantic slope specimens in their undivided or pinnate leaves with raised adaxial veins. They differ in their shorter plant height, shorter leaf sheaths, shorter and thinner rachis, more pinnae, wider basal pinna angles, shorter and thinner apical pinnae, thinner peduncles, and shorter rachillae.
There are three unplaced specimens from this region. Two specimens (
Grayum 5960, Jiménez 891
) from the Montañas
Jamaica
have smaller, undivided leaves with less pronounced raised veins. One specimen (
Davidse 26231
) from the Cordillera de Talamanca has orange-brown petioles and rachis.
In western
Panama
in the Fortuna area (
fortuna
morphotype), in
Chiriquí
and
Bocas del Toro
, there is a homogeneous morphotype from higher elevations (
1180 m
mean elevation), compared with
496 m
mean elevation for Atlantic and Pacific slope morphotypes. All specimens except one have undivided leaves with raised adaxial veins, and small inflorescences. Specimens differ from the nearest others, the Atlantic slope morphotype in
Costa Rica
, in their shorter petioles, shorter and narrower rachis, narrower basal pinna angles, narrower peduncles, and shorter and thinner rachillae.
There is a similar morphotype from the Santa Fé region in
Panama
(
santafe
morphotype). Specimens have undivided or pinnate leaves with raised adaxial veins. They differ from Fortuna specimens in their longer petioles, more pinnae, wider basal pinna angles, and shorter apical length. About half the specimens have pinnate leaves, which accounts for their wider basal pinna angles. This morphotype also occurs at lower mean elevations than the
fortuna
morphotype (888 versus 1140) m.
At the eastern end of the Central
Cordillera
at El Copé and the Coclecito Road (
elcope
morphotype) there is a morphotype with smaller, pinnate leaves and a slender, short rachilla. Specimens differ from
Santa Fé
ones in nine variables, particularly in their smaller leaves.
At El
Valle
and El Copé (
elvalle
morphotype) there is a morphotype with larger, undivided or pinnate leaves with pronounced adaxial veins and long, stout rachillae.
Specimens from Río Guanche, Santa Rita Ridge, Cerro Bruja, and Serranía de San Blás (
guanche
morphotype) are particularly variable, especially in rachilla size. They have undivided or pinnate leaves with pronounced adaxial veins. Some specimens have leaves which dry a gray-green color.
Some specimens from the Serranía de San Blás (
sanblas
morphotype) have small, usually undivided leaves with raised veins and small inflorescences.
In northwestern
Colombia
and just reaching eastern
Panama
, with an outlier on the Sierra Nevada de Santa Marta there is a morphotype (
cuneatoidea
morphotype) with large, undivided leaves or with 2–8 pinnae per side with pronounced raised veins and large inflorescences. The
type
of
G. cuneatoidea
is of this morphotype.
In the northern half of the
Chocó region
, and extending into eastern
Panama
, the Magdalena valley, the Central and Western Cordilleras, and western
Venezuela
is a morphotype (
choco
morphotype) with leaves with 3–7 pinnae per side, rarely undivided, and raised adaxial veins. Two specimens (
Bernal 2174, Juncosa 1228
) from this area are unplaced. They are similar to
subsp.
indivisa
except they have orange-brown petioles and rachis.
Stauffer (1998)
reported that
G. cuneata
occurred in
Apure
,
Venezuela
. The specimens cited by Stauffer have not been seen, but another specimen from the same locality is here determined as
G. brongniartii
.
Geonoma cuneata
does, however occur in
Zulia
,
Venezuela
in its
cuneatoidea
morphotype.
In northwestern
Colombia
, southwestern
Colombia
, and northwestern
Ecuador
(
multipinnate
morphotype), there is a pinnate leaved morphotype with 6–35 pinnae per side of the rachis, raised adaxial veins, and large inflorescences. There is no significant difference in any variable between the two areas where this morphotype occurs.
In western
Ecuador
(
Esmeraldas
) and extreme southwestern
Colombia
(
esmeraldas
morphotype) at low elevations (
50–350 m
), a few specimens, have small, undivided leaves with raised adaxial veins.
In western
Ecuador
and just reaching southwestern
Colombia
(
ecuador
morphotype) at higher elevations (
200–1375 m
) there is a morphotype with large, undivided or divided leaves with 2–6 pinnae per side of the rachis and prominent raised adaxial veins. This morphotype differs from the similar
cuneatoidea
morphotype in its narrower rachis and shorter rachillae. The specimen from the most southerly location (
Jativa
231
) is smaller than the others.