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
60c.
Geonoma stricta
subsp.
arundinacea
(Martius) Henderson
,
comb. & stat. nov.
Basionym:
Geonoma arundinacea
Martius (1823: 17)
.
Lectotype
(selected by
Wessels Boer 1968
):
BRAZIL
. Amazonas: “Rio Negro”, no date,
C. Martius s.n.
(
lectotype
M!).
Geonoma pycnostachys
Martius (1823: 16)
. Type:
BRAZIL
. Amazonas: Rio Japurá, no date,
C. Martius s.n.
(
holotype
M!).
Geonoma stricta
var.
trailii
(Burret)
Henderson (1995: 288)
.
Geonoma trailii
Burret (1930a: 178)
.
Geonoma elegans
Martius var.
amazonica
Trail (1876: 324)
. Type:
BRAZIL
. Amazonas: Rio Purus, Barreiras de Mancira,
29 September 1874
,
J. Trail 1032/CXXXIII
(
holotype
K!).
Geonoma piscicauda
Dammer (1907: 123)
.
Geonoma stricta
var.
piscicauda
(Spruce)
Henderson (1995: 287)
. Type:
BRAZIL
.
Acre
: Rio Juruá, Juruá-mirim,
May 1901
,
E. Ule 5520
(
holotype
B, destroyed, isotypes F!, K!, MG!).
Geonoma wittiana
Dammer (1907: 124)
. Type:
BRAZIL
.
Acre
: Rio Juruá, Juruá-mirim,
September 1901
,
E. Ule 5884
(
holotype
B, destroyed, isotype MG!).
Geonoma uleana
Dammer (1907: 122)
. Type:
BRAZIL
.
Acre
: Rio Juruá, Cachoeira,
May 1901
,
E. Ule 5521
(
holotype
B, destroyed, isotype MG!).
Geonoma trauniana
Dammer (1907: 124)
. Type:
BRAZIL
.
Acre
or Amazonas: Rio Juruá, Fortaleza,
October 1901
,
E. Ule 5946
(
holotype
B, destroyed, isotype MG!).
Geonoma dasystachys
Burret (1930a: 251)
. Type:
BRAZIL
. Amazonas: Rio Negro, Jauapasse assu,
5 July 1874
,
J. Trail 981/XC
(
holotype
K!).
Geonoma bella
Burret (1935b: 304)
. Type:
BRAZIL
. Amazonas: Mun. Tefé, Paranagua,
22 May 1933
,
B. Krukoff 4543
(
holotype
B, destroyed, isotypes F!, M!, MO!, NY!,
US
!).
Leaves
undivided or pinnate; veins raised and rectangular in cross-section adaxially, or not raised or slightly raised and triangular in cross-section adaxially; pinnae 2(1–12) per side of rachis.
Inflorescences
unbranched or branched; staminate flowers deciduous or persistent after anthesis.
Distribution and habitat:—
From
2°30’N–
17°50’S
and 49°32’–
78°42’W
in the western Amazon region of
Venezuela
,
Colombia
,
Ecuador
,
Peru
, and
Brazil
and eastern Andean slopes in
Ecuador
, at 416(75–1850) m elevation in lowland or montane rainforest (
Fig. 38
).
This is a widespread and extremely variable subspecies which can be divided into various morphotypes, mostly based on leaf size and shape.
In the western Amazon basin of
Colombia
,
Ecuador
,
Peru
, and
Brazil
there is a morphotype (
arundinacea
) with undivided or pinnate leaves with non-raised adaxial veins and unbranched or branched inflorescences with deciduous staminate flowers. In some cases specimens approach those of the
trailii
morphotype and are only distinguished by their non-raised adaxial veins. For example, in Yasuni National Park in Amazonian
Ecuador
, there are two forms of this morphotype. One has smaller leaves and branched inflorescences, the other larger leaves and unbranched inflorescences. The latter exactly resemble
trailii
in their leaves, except for the non-raised veins. There are no specimens of
trailii
from Yasuni, but it occurs just to the west of the Park. There may be introgression between
arundinacea
and
trailii
in this area. A specimen (
Vásquez 7413
) from Amazonian
Peru
has an exceptionally long rachilla.
On eastern Andean foothills and in the western Amazon region in
Colombia
,
Ecuador
, and
Peru
there is a morphotype (
elevata
) with small, undivided leaves with narrow basal angles and raised adaxial veins and unbranched inflorescences with persistent staminate flowers. Inflorescences are usually pendulous.
In the western Amazon region in
Colombia
,
Peru
, and
Brazil
there is a morphotype (
minor
) with small, undivided, rarely pinnate leaves and unbranched inflorescences with deciduous staminate flowers. Veins are difficult to score in this morphotype.
In the western Amazon region in
Colombia
,
Ecuador
,
Peru
, and
Brazil
there is a morphotype (
piscicauda
) with large, undivided leaves with narrow basal angles and raised adaxial veins. Inflorescences are unbranched and often pendulous, and have persistent staminate flowers. The
types
of
G. piscicauda
and
G. wittiana
are of this morphotype.
On eastern Andean foothills in
Ecuador
at 1217(825–1600) m elevation there is a morphotype (
puyo
) with pinnate leaves and branched or unbranched inflorescences with deciduous staminate flowers. Veins are difficult to score in this morphotype, and there seem to be several local variants. Some specimens (
Balslev 6419, Cerón 6552, 7454, Harling 3762
,
Øllgaard 98478
) have exceptionally long inflorescences.
A widespread morphotype (
pycnostachys
, Plates XX, XXI) occurs in the central and western Amazon region in
Venezuela
,
Colombia
,
Ecuador
,
Peru
, and
Brazil
. It has mostly undivided leaves with the veins not raised adaxially, and unbranched inflorescences with persistent staminate flowers. The
type
of
G. pycnostachys
is of this morphotype. Several specimens from the central Amazon region (
Campos 519, Cid 545, Henderson 662, 1043, 1066, Nee 42341, 42897
) are more similar to
subsp.
stricta
in their small leaves than they are to other, more westerly specimens of
pycnostachys
. However, small-leaved
pycnostachys
also occur sporadically in the western Amazon region. Specimens (
Díaz 7327, Kajekai 300, Rodríguez 261, 568, Rojas 592, Vásquez 18741, 20286, 24195, 24322
) from southeastern
Ecuador
and northwestern
Peru
(Amazonas) have exceptionally large leaves, thick rachillae, and large fruits. Specimens from eastern Andean slopes in
Ecuador
have pinnate leaves with few divisions. Some specimens (e.g.,
Lewis 10332, Vásquez 14439
, and probably several others) appear to be hybrids between this and the
trailii
morphotype, and others appear to be hybrids between this and the
piscicauda
morphotype.
In the central and western Amazon region of
Colombia
,
Ecuador
,
Peru
,
Bolivia
, and
Brazil
, with outliers in the central Amazon of
Brazil
and in
Bolivia
, there is a morphotype (
trailii
) with pinnate leaves with raised adaxial veins and unbranched inflorescences with deciduous staminate flowers. The
types
of
Geonoma elegans
var.
amazonica
,
Geonoma trauniana
,
Geonoma dasystachys
,
and
Geonoma bella
are of this morphotype. The two outlying specimens in
Bolivia
occur in the same area as outlying specimens of the
tapajotensis
morphotype of
G. macrostachys
.
As in the
pycnostachys
morphotype, specimens from southeastern
Ecuador
and northwestern
Peru
(Amazonas) have exceptionally large inflorescences.
In the southwestern Amazon region in
Peru
and
Brazil
there is a morphotype (
uleana
) with undivided or pinnate leaves with non-raised adaxial veins and unbranched inflorescences with deciduous staminate flowers. It has longer peduncular bracts—3.5 (2.7–4.7) versus 0.5(0.1–4.0) cm—than other morphotypes. The
type
of
G. uleana
is of this morphotype.