The genus Disperis (Orchidaceae) in Madagascar, the Comores, the Mascarenes and the Seychelles
Author
Croix, Isobyl la
Author
Bosser, Jean
Author
Cribb, Phillip J.
text
Adansonia
2002
3
24
1
55
87
journal article
http://doi.org/10.5281/zenodo.5180356
1639-4798
5180356
6.
Disperis ciliata
Bosser
,
sp. nov.
Affinis
Disperis
latigaleatae H. Perrier
sed petalis ad marginem ad apicemque longe ciliatis, et lobo mediale labelli triangulare satis differt.
TYPUS
. —
Humbert
&
Capuron
25002
,
Madagascar
, mountains
N
of
Mangindrano
(High Maevarano, near the summits of Ambohimiravavy (Central–North),
1800-2000 m
,
19 Jan.-12 Feb. 1951
(holo-,
P
!; iso-,
K
!,
MO
!,
P
!). Known only from the
type
collection.
A terrestrial herb,
15-20 cm
tall. Stem slender glabrous. Leaves 2, opposite, inserted shortly above the middle of the stem, lanceolate, acute, rounded at the base and retracted into a short petiole, 2-4.5 ×
0.8-2 cm
. Inflorescence 2-5-flowered; bracts ovate, acute, those at the base largest, leafy, up to 8 ×
5 mm
. Flowers rose-coloured; pedicel and ovary
7-10 mm
long. Dorsal sepal narrowly lanceolate to linear, acute, 7 ×
1.5 mm
, glabrous, with a median nerve and two fine lateral ones. Lateral sepals obliquely and broadly ovate, obtuse, connate at the base for about
2.5 mm
, lacking a spur or gibbosity, 7.5 ×
5.5 mm
. Petals broadly and obliquely ovate, 6-6.5 ×
4.5 mm
, rounded at the tips, with the margins and apical part longly ciliate, adnate to the dorsal sepal to form a very concave hood of 6 ×
6 mm
. Lip
3-3.5 mm
long; basal part linear, attached to the column for
1.7-1.9 mm
; terminal part enlarged into a trilobed appendix, the lateral lobes linear, curved, involute on the margins, dilated-claviform at the apex, more or less
2 mm
long; mid-lobe triangular, of the same length or a little longer than the side lobes, the upper face of the 3 lobes densely covered with a short papillose pubescence. Rostellar arms
1.7-1.8 mm
long, slightly curved and spathulate at the apex. —
Fig. 6D.
DISTRIBUTION. —
Madagascar
; endemic.
HABITAT. — Under trees in humid montane forest on laterite of gneiss, transition to lichenrich forest;
1700-1900 m
.
Because of its habit and the general appearance of its flowers, this species recalls
D. latigaleata
. It can be readily distinguished, however, by its ciliate petals and by the terminal appendage of its lip in which the midlobe is relatively short and covered by a short papillate pubescence while in
D. latigaleata
that lobe is lengthened into a linear glabrous extention which is slightly dilated at the tip. The lip appendage also resembles that of some forms of
D. oppositifolia
, but the flower is glabrous, with the lateral sepals more extensively connate and contracted at the narrow base.