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
15.
Disperis humblotii
Rchb.
f.
Flora 68: 377 (1885)
; Schlechter, Bull. Herb. Boiss.
6: 954 (1898),
in syn
; H. Perrier in Humbert H. (ed.),
Fl. Madag., 49
e
fam.,
Orchidées 1: 191 (1939)
; Du
Puy et al., Orch. Madag.: 135 (1999)
. —
Type
:
Humblot s.n
.,
Comores
(holo-, W!).
Disperis comorensis
Schltr.
in
Engler
,
Bot. Jahrb. Syst.
24: 429 (1897)
;
Bull. Herb. Boiss.
6: 946 (1898);
Feddes Repert. Spec. Nov. Regni
Veg. Beih. 33: 107 (1925)
;
H.
Perrier
,
Not. Syst.
(Paris) 5: 227 (1936)
; in
Humbert
H. (ed.),
Fl. Madag.
, 49
e
fam.,
Orchidées
1: 192 (1939)
;
Du Puy
et al.,
Orch. Madag.
: 134 (1999)
. —
Type
:
Bang
s.n
.,
Comores
, in Herb. Schlechter (holo-, B delet.);
syn. nov.
A slender glabrous, terrestrial herb,
10-22 cm
tall. Leaves 2-3, alternate, set around the middle of the stem, lamina narrowly ovate to ovate, acute at the apex, cordate at the base, 2-4 ×
1- 2 cm
, the lower one long petiolate, petiole
4- 7 mm
long, the upper leaf sessile. Inflorescence 2-10-flowered; bracts lanceolate or ovate, acute, generally shorter than the ovary,
5-8 mm
long. Flower rose-coloured or white. Dorsal sepal narrow, one-nerved, forming an oblong hood with the petals, 6-7 ×
2.5-3 mm
. Lateral sepals narrowly ovate, 9-10 ×
2.5-3 mm
, slightly falcate, obtuse at the apex, adnate in the basal quarter to half their length, 3-4-nerved, bearing an obtuse conical spur,
0.6-0.7 mm
long, in the basal third. Petals linear-ligulate,
6-7 mm
long. Lip
2 mm
long, basal part linear, united to the column; terminal part 3-lobed; the two lateral lobes slightly divergent, oblong,
1.2- 1.5 mm
long, rounded at the tips, concave on the inner face, outer face papillose-pubescent; mid-lobe stalked, fleshy, saddle-shaped,
1.5- 2.8 mm
long, obtuse at the tip, rounded and gibbous at the base, upper surface shortly papillose-pubescent, but the gibbous base is quite glabrous; stipe linear, glabrous, flat,
2 mm
long, attached to the basal third to the terminal appendage Rostellar arms short,
0.8 mm
long, spathulate at tips. stigma transverse, subreniform. —
Fig. 6G.
DISTRIBUTION. —
Madagascar
,
Comores
. HABITAT. — Under trees in humid forest at intermediate elevations;
700-1400 m
.
MATERIAL STUDIED. —
MADAGASCAR
:
Decary
12
,
Ambohimanga
,
25 Aug. 1920
(
P
!)
;
Humbert
&
Cours
17804
,
Andrangovolo Massif
, SE of
Lake Alaotra
,
Res. Nat.
no. 3 of
Zahamena
, basin of the
Onibe
,
1200-1400 m
,
Oct. 1937
(
P
!)
;
Perrier de la Bâthie
11880
,
Analamazaotra
,
Périnet
800 m
,
July 1913
(
P
!)
;
Perrier de la Bâthie
17740
,
Ambre forest
,
700 m
,
Aug. 1926
(
P
!)
. —
COMORES
:
Benson
84
,
Niombadjou
,
Grande Comore
, 15
Aug.
(
P
!)
;
Bernard
s.n
., M’zoudi hill,
Anjouan
,
27 Aug. 1903
(
P
!)
;
Bosser
s.n
.,
Anjouan
, 1963 (
P
!)
;
Humblot
s.n
., without exact loc. (
W
)
;
Humblot
1592 (592),
without exact loc. (
P
!)
.
REICHENBACH (l.c.) did not cite a number for the
type
specimen of this obscure species, and the flower on the sheet in the REICHENBACH herbarium in Vienna is in poor condition. However, in his protologue, REICHENBACH gave the characteristics of the lip that correspond well with the herbarium material from
Madagascar
and the
Comores
cited above under
D. humblotii
. He said of the lip: “lamina mediana bene unguiculata, oblonga, velutina basi superiore excepta”. This last detail is characteristic of this species. With regard to
D. comorensis
, we have not seen the
type
,
Bang s.n
., which was in SCHLECHTER’
S
herbarium (
B
) which was destroyed, but the description of the lip is sufficiently clear for us to concur that it belongs to the same species:
“labello…antice tertia parte bifido, segmentis erectis, obtusis, medio antice in processum arcuatoadscendentem graciliter unguiculatum, subpeltatum, lamina carnosa, sigmoidea, utrinque obtusa papillosa
”. Although he did not mention the glabrous basal part of the terminal appendage of the lip, the term sigmoid describes its saddleshaped form. On the other hand, SCHLECHTER attributed
Humblot 1592
(
P
) to his
D. comorensis
and it is possible that the herbarium specimen of HUMBLOT found in Vienna, the
type
of
D. humblotii
, was a part of that collection.
Although there are few Madagascan collections, the distribution of the species is extensive, ranging from around Antananarivo to Périnet (Andasibe) to
Lake Alaotra
and
Mt. Ambre. In
the
Comores
, it has been found on
Grande Comore
and
Anjouan
but it is very local
.
The flower recalls somewhat that of
D. lanceana
, but the terminal appendage of the lip is larger and of a diffferent form.