A revision of the endemic Malagasy genus Beguea (Sapindaceae)
Author
George E. Schatz
Africa and Madagascar Program, Missouri Botanical Garden, P. O. Box 299, St. Louis, MO 63166 - 0299, U. S. A.
george.schatz@mobot.org
Author
Roy E. Gereau
Africa and Madagascar Program, Missouri Botanical Garden, P. O. Box 299, St. Louis, MO 63166 - 0299, U. S. A.
Author
Porter P. Lowry Ii
Africa and Madagascar Program, Missouri Botanical Garden, P. O. Box 299, St. Louis, MO 63166 - 0299, U. S. A. and Institut de Systématique, Evolution, et Biodiversité (UMR 7205 - CNRS MNHN UPMC EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, C. P. 39, rue Cuvier 57, 75231 Paris CEDEX 05, France
text
Candollea
2017
2017-03-30
72
1
45
65
journal article
32147
10.15553/c2017v721a6
c05afdbe-5c00-406f-abf5-69a53d227a8b
2235-3658
888177
1.
Beguea ankeranensis
G.E. Schatz & Lowry
,
spec. nova
(
Fig. 1
,
2
A).
Typus
:
MADAGASCAR
.
Prov. Toamasina
:
Atsinanana Region
,
Brickaville
,
Anjahamamay
,
Anivoranokely
,
Ankerana forest
,
18̊24’21’’S 48̊48’18’’E
,
700 m
,
19.I.2012
, fl.,
Antilahimena
7978
(
holo-
:
MO-6704230!
;
iso-
:
G
[
G00341688
]!,
K
!,
P
[
P00580357
]!
TAN
).
Haec species a congeneris foliorum petiolo rhachideque indumento aureobrunneo tomentulosis, foliolis 6 ad 8 in sicco complanatis apice acute acuminatis, pedicellis c. 1 mm longis atque antheris 2.2-2.5 mm longis distinguitur.
Tree
c. 15 m tall; stems densely golden brown tomentulose. Petioles 2.6-4 cm, densely golden brown tomentulose.
Leaves
with 6-8 subopposite to alternate leaflets; rachis 3.8-7 cm, keeled above, golden brown tomentulose; petiolule 2.5-3 mm, golden brown tomentulose; leaflet blade 2.8-7 × 1.2-2.2 cm, elliptic, papyraceous to subcoriaceous, flat in pressed material, glabrous and only slightly glossy above, sparsely light brown tomentulose on midvein and secondary veins below, base weakly to markedly asymmetrical, acute to nearly decurrent, margins minutely thickened, not revolute, apex distinctly acuminate, the acumen acute, midvein distinctly raised and knife-like above and below, secondary veins (8-)10-13 per side, flat to slightly impressed above, raised below, tertiary venation obscure above, slightly raised and evident below.
Inflorescence
axis 16-19 cm long, c. 1 mm in diam., unbranched, dark chocolate brown, densely golden brown tomentulose; bracts c. 1 mm, narrowly triangular, adaxially concave; pedicels c. 1 mm, c. 0.8 mm in diam., densely golden brown tomentulose.
Male flowers
with a shallowly cupulate, (4-)5-lobed calyx, the lobes broadly triangular, c. 1 × 1.2 mm, acute, densely golden brown tomentulose outside, densely golden setaceous inside; stamens 8, filaments 1-3 mm, glabrous, anthers 2.2-2.5 × c. 0.8 mm, ellipsoid; disc and pistillode densely golden setaceous, the trichomes to 0.5 mm.
Female flowers
not seen.
Fruit
not seen.
Conservation status
. – Known only from a single collection from well within an intact forest block of the newly designated Corridor Ankeniheny Zahamena PA (
Fig. 3
), and lacking any additional information on population size,
B. ankeranensis
is assigned a provisional status of “Least Concern” [LC] using the IUCN Red List Criteria (
IUCN, 2012
), with the caution that this status is highly dependent on continued effective protection.
Notes
. –
Beguea ankeranensis
is known only from the type collection in humid forest at Ankerana (
Fig. 3
), which is included within the recently decreed Corridor Ankeniheny Zahamena PA. It can be easily distinguished from the two species most similar morphologically (
B. birkinshawii
and
B. turkii
) by its leaflets with a long-acuminate apex and an acute acumen (vs acute to short acuminate apex and rounded to retuse acumen), short pedicels c. 1 mm long (vs 2.5-4 mm long), and large anthers 2.2-2.5 mm long (vs only 1 mm long) (
Fig. 1
,
2
A).