A synopsis of the Malagasy endemic genus Megistostegium Hochr. (Hibisceae, Malvaceae)
Author
Koopman, Margaret M.
text
Adansonia
2011
3
2011-06-30
33
1
101
113
http://dx.doi.org/10.5252/a2011n1a7
journal article
10.5252/a2011n1a7
1639-4798
5197059
Megistostegium nodulosum
(Drake) Hochr.
Annuaire du Conservatoire et du Jardin botanique
de
Genève
18-19: 228 (1915). — Basionym:
Hibiscus
nodulosus
Drake,
Bulletin du Muséum national d’Histoire
naturelle
Paris 9: 38 (1903)
. —
Type
:
Madagascar
,
Faux
Cap, arbre de la brousse épineuse.
15 VII 1901
,
G
.
Grandidier s.n.
(P).
Macrocalyx tomentosa
Costantin & Poisson,
Comptes Rendus des Séances de l’Académie
des
Sciences Paris
147: 637 (1908). —
Type
:
Madagascar
,
Tulear
,
Massif de la Table
,
F. Geay 5295
,
5301
(P).
Macrocalyx tomentosa
var.
rubra
Poisson,
Recherches
sur la flore méridionale de
Madagascar
: 27 (1912). —
Type
:
Madagascar
, plante en buisson à aspect
de Rhododendron
, fleur rouge, pentes arides au-dessus des grottes
d’Andrahomena
(Sud),
Alluaud
19
(P).
Megistostegium retusum
Hochr.,
Annuaire du Conservatoire et du Jardin
botanique
de Genève
18: 227 (1915)
. —
Holotype
:
Madagascar
, sud-ouest, dunes au sud du lac
Tsimanampetsa
ou
Mananpetsa
,
VI.1910
,
Perrier de la Bâthie
5472
(=
Hochreutiner 16
) (G).
Megistostegium retusum
fma.
humbertii
Hochr.
nom. nud.
,
in sched
.
Madagascar
,
environs
de
Tulear
, delta
de
Fiherenana
, lieux sablonneux, dunes, arbuste, fleurs rouge vif.
14-26.IX.1924
,
Humbert
&
Perrier de la Bâthie
2535
(
A
,
B
,
US
)
.
ADDITIONAL MATERIAL EXAMINED. —
Madagascar
.
Prov. Efotsy
(S-O),
2.III.1955
,
J
.
Bosser
53
(
MO
). —
Itampolo
(S-O),
2.III.1955
,
J
.
Bosser
68
(
MO
). —
Route
Betioky-
Soalary
,
2.II.1968
,
J
.
Bosser
19293
(
P
,
MO
). —
SW
,
Bush
entre Atanadebo et Behara
(aux confins des districts
de Ft. Dauphin
et
Ambovombe
),
29.IX.1957
,
R
.
Capuron
8535-
SF
(
P
). —
Route d’Ifaty Tulear
,
31.VIII.1965
,
F
.
Chauvet
106
(
P
). —
Open
woodland,
12 km
N
of
Toliara
on road to
Morombe
near sea level,
5.II.1975
,
T
.
B
.
Croat
30793
(
MO
). —
Au
nord
d’Ambatomainty Ambovombe
,
30.
I
.1932,
R
.
Decary
9591
(
P
). —
Haute
vallée
du Manambolo
,
25.XI.1935
,
R
.
Decary
9406
(
P
). —
Behara
(près de
Fort Dauphin
),
11.VII.1930
,
R
.
Decary
4280
(
P
). —
Ambovombe
(
Behara
),
10.
I
.1935,
R
.
Decary
8379
(
P
,
MO
). —
Coastal
plain,
12 km
N
of
Toliara
, on RN9, 1 km
S
of Tsangoritelo
,
23°23’S
, 43°63’E,
1.II.1994
,
B
.
Du Puy
et al.
MB580
(
MO
). —
SW
,
Province
of
Toliara
(
Tulear
),
NW of
Toliara
,
Forest of Mikea
,
c
.
13 km
N
of the mouth of the
Manombo River
, near the coast,
22°44’S
,
43°20’E
, alt.
30 m
,
4.XII.1993
,
Du Puy
et al.
M692
(
MO
,
P
). —
Cultivated
at the
USDA
plant introduction station,
Miami
FL
P
.
I
.
No.
77929, introduced from south of
Lake Tsimanampetsotsa
,by
Charles Swingle
and
Henri Humbert
,
22.
I
.1974,
W
.
T
.
Gillis
8876
(
MO
). —
Environs de Tulear
, coteaux calcaires (
La Table
),
8.VIII.1932
,
H
.
Humbert
&
C
.
F
.
Swingle
5208
(
P
). —
Environs de Tulear
, delta du
Fiherenana
, lieux sablonneux, dunes, alt.
2-10 m
,
14-26. IX.1924
,
H
.
Humbert
&
H
.
Perrier de la Bâthie
2535
(
P
). —
N
coastal road out of
Tulear
,
35-50 km
N
(road to
Morambe
)
,
23°12’S
,
43°37’E
, alt.
0-20 m
,
12.XI.1993
,
R
.
C
.
Keating
&
J
.
S
.
Miller
2242
(
MO
). —
Bevato Nord
,
5.IX.1972
,
B
.
Koechlin
s.n.
(
P
). — Bevato Nord sur calcaire et sable, 1967-1969,
B
.
Koechlin
s.n.
(
P
). —
N
of
Toliara
on coastal track between
Manambo
and
Salary Forest
,
c
.
3 km
N
of Tsifota village
,
5.VIII.1997
,
B
.
Lewis
518
(
MO
). —
Toliara
, approximately
15-20 km
N
of Ifotsy
on the road to
Beheloka
, alt.
50 m
,
2.II.2002
,
M
.
Luckow
4325
(
MO
). —
SW
,
P
.
Montagnac
130
(
P
). —
Soalara
,
2.III.1908
,
P
.
Morat
672
(
P
). — Entre Vohombe et Lambetamasay,
2.
VI
.1932,
G
.
Petit
s.n.
(
P
). —
Réserve d’Andohahela
,
Parcelle
2;
NE
of Amboasary
near
Hazofotsy
,
24°50’S
,
46°32’E
, alt.
100 m
,
8.XII.1992
,
P
.
B
.
Phillipson
2842
(
MO
). —
R
.
N
.
X.
Tulear
,
12.
I
.1952,
Ravelonjarahony
3637
(
P
). —
Near Songeritelo
,
N
of
Tuléar
,
14 km
N
of Fiherenana River Bridge
, on
E
side of road,
23°23’S
,
43°37’E
,
24.III.1988
,
T
.
Willing
74
(
MO
). —
19 km
E
of Beloha on Tsihombe Road
,
Tulear
,
25°17’S
,
45°03’E
,
4.XI.1989
,
T
.
Willing
8
(
MO
)
.
DESCRIPTION
Tree up to
8 m
tall. Leaves well distributed along the entirety of the branches, gray-green, thin, flexible, orbicular (1.1-3.96 ×
1.4-3.9 cm
) with a distinctive cordate base and downy tomentum. Stipules filiform. Flowers erect. Epicalyx lobes somewhat rounded at the apex, light pink/red in color. Corolla red/pink and does not form a cup but instead has an open architecture in which petals do not overlap each other. Staminal column long, exserted past the corolla, up to
5 cm
long, curved, making the flower zygomorphic in form (
Fig. 1
). Pollen yellow when fresh, average diameter 110 µm with echineae 12.4µm tall × 7.8 µm wide and 2 µm wide apertures.
DISTRIBUTION AND ECOLOGY
Megistostegium nodulosum
has the largest range of the three species, extending from north of
Toliara
in the west to north of Tranomaro near the transitional forest to the southeast (
Fig. 2
). The species appears to be restricted to sandy habitats and at CSM grows in soils that average
34.87 cm
(± 0.49) in depth. This species has been collected throughout the year but most collections are from November through mid-March, with a second peak in August through September (single specimens exist from June and July).
REMARKS
Ethnobotany
The strong wood of this species is used regularly for house construction (major structural beams), charcoal for cooking and as a torch by which to fish for lobster at night (pers. obs.). One mention is made of using the wood of
Megistostegium nodulosum
(as
Macrocalyx tomentosa
;
Costantin & Poisson 1908
) for nails to assemble pirogues. A powder of the bark and branches are used in the same way as in the previous species.
Vernacular names
Vonkara,Tsomotsoy (Somontsoy),Tsomotsoy lahy, Sognogne.
CONSERVATION STATUS
Megistostegium nodulosum
has the widest distribution of the three species (EOO of
c
.
56000 km
2, and an AOO exceeding
2000 km
2) and resides inside three
protected areas. The current conservation status is deemed Near Threatened (NT), because populations will likely approach a 30% reduction in size over the next three generations, given current ethnobotanical practices and the fact that the species is highly sought after for its strong wood.