Terminalia carinata Sabatier & J. Engel, sp. nov. (Combretaceae), a new large tree species from the Guiana shield revealed by re-examination of material previously identified as T. guyanensis Eichler
Author
Engel, Julien
Author
Sabatier, Daniel
text
Adansonia
2020
3
2020-11-02
42
16
261
271
journal article
8801
10.5252/adansonia2020v42a16
9d5d9cb4-e64f-4402-981a-7844a361f562
1639-4798
4447985
Terminalia guyanensis
Eichler
in
Mart.
(
Figs 3
,
4
,
5
,
6
)
Flora Brasiliensis
14 (2): 88 (1867). —
Myrobalanus eichleriana
Kuntze,
Revisio Generum
Plantarum
1: 237 (1891), nom. nov. pro
Terminalia guyanensis
Eichler
, non
Myrobalanus guianensis
Kuntze (1891)
, nec.
Terminalia eichleriana
Alwan & Stace (1989)
. — Typus:
French Guiana
. 1817-1822,
Poiteau
s.n.
(
holo-
,
B
, destroyed, photograph at
FI
;
iso-,
K
[
K000640657
],
P
[
P01901252
,
P01901253
,
P01901254
]!,
U
[
U0001197
],
W
[
W-Rchb. 1889-0125487
]);
No collector
(probable iso-,
A
/
GH
[
GH00068628
]).
DISTRIBUTION. — The specimens consulted were collected in
Venezuela
and French Guiana. It is very likely that
T. guyanensis
also occurs in the region between these two countries, which would include
Guyana
,
Suriname
and adjacent areas in
Brazil
.
HABITAT. — According to herbarium sheets and inventory data from the GUYADIV and GUYAFOR networks (
Engel 2015
),
T. guyanensis
is encountered in
terra-firme
forest between
100 to 810 m
elevation. Its privileged habitat seems to be cloud forest and very rainy forest receiving more than
3500 mm
of precipitation per year. PHENOLOGY. — Flowers were collected in November during leafless stage, fruits in March and May.
CONSERVATION STATUS. — Based on the herbarium sheets consulted,
T. guyanensis
is known from five localities in French Guiana and two localities in
Venezuela
. Outside one site in French Guiana (Mont Itoupé) where
T. guyanensis
is relatively common, the authors rarely encountered this species during the inventory work carried out as part of the GUYAFOR and GUYADIV networks. More precisely, out of the almost 180 000 trees inventoried in these two networks, only 12 were identified as
T. guyanensis
. The calculated AOO is
32 km
², the calculated EOO is
138589 km
² which is very high as this species has been collected in
Venezuela
and French Guiana and is thus very likely to also occur in
Guyana
and
Suriname
. In countries where
T. guyanensis
has been collected, as well as in countries where this species is probably present, the forest massif is generally (still) preserved.
Terminalia guyanensis
is thus classified as Least Concern (LC) following the IUCN Red List criteria (
IUCN 2012
). However, even if the forest massif is not directly threatened by human activities,
T. guyanensis
is one of the many rare Amazonian tree species with low densities and unknown ecological requirements and whose regeneration could potentially be affected by climate change (
ter Steege
et al.
2013
; Esquivel-Muelbert
et al.
2018).
AFFINITIES. — Like 14 other neotropical
Terminalia
,
T. guyanensis
has 2-winged fruits, each wing>
1 cm
long. But only
T. argentea
Mart. & Zucc.
,
T. januarensis
DC.
and
T. phaeocarpa
Eichler
have quite similar fruit body, bulging on both faces, although often with a slight ridge or slightly wavy while the surface of
T. guyanensis
fruit body is rounded and smooth. Vegetatively, these three species can be distinguished from
T. guyanensis
by their pubescent or subglabrous leaves (but at least they are pubescent on main veins abaxially) while
T. guyanensis
leaves are glabrous. If we consider more specifically the 15 species of
Terminalia
found in
French Guiana
(including
T. carinata
Sabatier & J.Engel
,
sp. nov.
), five are immediately distinguishable by the size of their leaves, which are clearly larger (
T. aubletii
Gere & Boatwr.
,
T. macrophylla
(Eichl.) Gere & Boatwr.
,
T. megalophylla
(Van Heurck & Müll.) Gere & Boatwr
, and
T. nitidissima
Rich.
), or smaller (
T. parvifolia
(Ducke) Gere & Boatwr.
) than those of
T. guyanensis
. And none of the other species has glabrous leaves with such brochidodromous veins with one or two sets of loops outside of the main brochidodromous loop.
FIG. 5. —
Terminalia guyanensis
Eichler
:
A
, fruiting branch;
B
, transverse section of fruit;
C
, inflorescences;
D
, longitudinal section (
left
) and lateral view (
right
) of flower;
A
,
B
,
Sabatier 6331
(CAY);
C
,
D
,
Sabatier & al. 6018
(P). Drawn by Laurence Ramon. Scale bars: A, B, 2 cm; C, 1 cm; D, 1 mm.
FIG. 6. —
Terminalia guyanensis
Eichler
:
A
, fruiting branch;
B
, inflorescences;
C
, trunk;
D
, bark with a machete slash;
A
,
Sabatier & Molino 5682
(CAY);
B -D
,
Sabatier et al. 6018
(P).
A -D
, Photographs by Daniel Sabatier.
OTHER MATERIAL STUDIED
. —
French Guiana
.
Mont Itoupé
,
430 m
,
3°1’21”N
,
53°6’29”W
, fl.,
17.XI.2014
,
Sabatier
et al. 6018
(
CAY
[-
CAY182882
!],
P
[
P01155923
!])
;
Mont Itoupé
, inv. code ITO1-
K
4, 600 m
,
3°1’20”N
,
53°5’29”W
, fr.,
12.III.2010
,
Sabatier
&
Molino
5682
(
CAY
[
CAY103783
!])
;
Mont Itoupé
,
433 m
,
3°2’22”N
,
53°6’19”W
, fr.,
13.III.2017
,
Sabatier
6331
(
CAY
[
CAY182884
!],
P
[
P01155924
!])
;
Mont Itoupé
, inv. code
ITOW
8-5, 328 m
,
3°3’18”N
,
53°6’34”W
, st.,
12.XI.2014
,
Sabatier
et al. 6051
(
CAY
[
CAY182883
!])
;
Mont Itoupé
,
3°1’18”N
,
53°7’10”W
,
200 m
, st.,
20.III.2010
,
Molino
&
Sabatier
2794
(
CAY
[
CAY104624
!],
MPU
)
;
Réserve Trésor
, inv. code
T
10380
, 235 m,
4°34’12”N
,
52°17’24”W
, st.,
1.IX.2008
,
Engel
et al. 16
(
CAY
[
CAY182881
!])
;
Massif Lucifer
, plateau
Tabulaire
,
530 m
,
4°47’11”N
,
53°55’23”W
, st.,
15.XI.1999
,
Dutreve
355
(
CAY
[
CAY046077
!])
;
Station des Nouragues
,
Bassin de l’Arataye
, inv. code
NOU3-146
,
4°3’N
,
52°42’W
, st.,
7.VII.1989
,
Sabatier
&
Prévost
2627
(
CAY
[
CAY010136
!],
LTR
)
;
Montagne de Kaw
, st.,
16.IX.1969
,
Petrov
203
(
CAY
[
CAY170282
!],
P
[
P04717175
!])
;
ibid.
,
17.IX.1969
,
Petrov
208
(
CAY
[
CAY182888
!],
P
[
P04717176
!])
.
Venezuela
.
Territorio
federal,
delta Amacuro
: bosque pluvial,
Este de Río Grande. Este-Noreste de El Palmar
, cerca de los limites del
Estado
Bolívar
, fr.,
23.
V
.1964
,
Marcano Berti
187
(
A
/
GH
,
BM
,
F
[
V0397201
F
],
MG
,
US
[
US00766632
],
VEN
)
;
East of Cerro El Picacho
,
near Las Nieves & Las Chicharras,
45 km
North of Tumeremo
,
600-650 m
, st.,
5-8.II.1961
,
Steyermark
89070
(
A
/
GH
,
P
[
P04717179
!],
S
,
VEN
)
.
DESCRIPTION
Deciduous canopy tree up to
60 m
tall, with thick, rounded buttresses to
1–2 m
high. Diameter up to
105 cm
. Bark brownyellow, densely scaly, inner bark pale yellow.Twigs pubescent, becoming glabrous; terminal buds densely pubescent. Leaves alternate, spirally arranged, usually clustered at branchlet tips; blades chartaceous, elliptic-oblong to elliptic, 5-13 ×
2-5 cm
; apex acuminate; base cuneate or attenuate-cuneate; margin entire; both surfaces glabrous, except rarely a tuft of hairs in axils of secondary veins abaxially; lateral veins 7-10, uniformly pinnate, intersecondary veins often present, brochidodromous, with one or two sets of loops outside of the main brochidodromous loop, slightly raised on both surfaces, lower venation randomly reticulate, visible on both surfaces; petioles
0.8-2 cm
, slightly pubescent or usually glabrous, often with a pair of small glands toward apex.
Inflorescences axillary, clustered in
c.
6-13 spikes at leafless branchlet-ends,
1.5-3 cm
long, covered by lanate trichomes,
c.
25-40-flowered; peduncle
0.4-1.1 cm
long; bracts inconspicuous and caducous. Flowers bisexual, pale yellowish, actinomorphic, 1.6-3 ×
1.5-2.3 mm
; lower hypanthium extended into a short “neck” surrounding the ovary,
0.8-1.5 mm
long, densely pubescent, upper hypanthium cupuliform to campanulate,
0.8-1.6 mm
long, pubescent on the external surface, lanate with much longer trichomes on the inner surface; calyx lobes 5,
0.6-1 mm
long, pubescent on the external surface, lanate with much longer trichomes on the inner surface; petals 0; stamens 10, white, glabrous,
2.1-2.8 mm
, anthers versatile,
c.
0.3 mm
long; intrastaminal disk
c.
1.2 mm
width, slightly lanate; ovary inferior, unilocular, style exserted,
2.4-3.7 mm
long, slightly lanate over about a third of its lower part. Infrutescence with 1-2 fruits, peduncle and rachis slightly pubescent or usually glabrous. Fruits 2-winged, dry, glabrous and shiny, 4.9-6.3 ×
1.8-2.4 cm
, apex shortly acuminate, flat or slightly emarginate, base obtuse; wings stiff, green, (sub) equal,
2-2.8 cm
long, rounded to narrowly rounded; body
c.
0.5-0.7 cm
wide,
c.
4 mm
high, bulging on both faces.
NOTE
We have previously discussed the confusion between
T. guyanensis
and
T. carinata
Sabatier & J.Engel
,
sp. nov.
Sterile specimens of
T. guyanensis
have sometimes also been confused with
T. dichotoma
G. Mey. Thus
, three specimens studied by the authors (
Sabatier & Prévost 2627
,
Petrov 203
and
Petrov 208
) and cited in the present study are recorded as
T. dichotoma
in
Stace (2010)
. These two species can be distinguished from each other by their venation pattern:
T. guyanensis
veins are more brochidodromous with one or two sets of loops (absent in
T. dichotoma
) outside of the main brochidodromous loop.