A revision and one new species of Begonia L. (Begoniaceae, Cucurbitales) in Northeast India
Author
Camfield, Rebecca
Author
Hughes, Mark
text
European Journal of Taxonomy
2018
2018-01-19
396
1
116
journal article
22365
10.5852/ejt.2018.396
2b95a851-e1bf-4bdd-9cce-441ddc4135d2
3787049
Begonia megaptera
A.DC. [sect.
Platycentrum
]
Fig. 39
Annales des Sciences Naturelles; Botanique
,
Sér
. 4,
11: 134 (de
Candolle 1859
)
. –
Type
:
India
,
Sikkim
,
1820–2420 m
,
Hooker 8
(lecto-: K, here designated).
Citations in other publications
de
Candolle (1864: 348)
,
Clarke (1879: 646)
,
Clarke (1881: 119)
,
Clarke (1890: 25)
,
Fischer (1938: 98)
,
Hara (1966: 214)
,
Hara
et al.
(1979: 182)
,
Grierson (1991: 245)
,
Kumar (2002: 647)
,
Kress
et al.
(2003: 171)
,
Uddin (2007: 594)
,
Hughes (2008: 80)
,
Khatun (2008: 10)
,
Dash (2010: 35)
.
Other material examined
INDIA
:
Arunachal-Pradesh
: Lohit Valley,
13 Feb. 1950
,
Ward 19146
(
BM
); Mishmi Hills, Kamlang River,
18 Mar. 1949
,
Ward 18420
(
BM
).
Meghalaya
: Garo Hills, Nokrek,
7 Mar. 1950
,
Chand 2753
(
MICH
); ibid.,
7 Mar. 1950
,
Chand 2759
(
MICH
); ibid.,
7 Mar. 1950
,
Koelz 24605
(
MICH
); Garo Hills, Tura Mountain,
20 Nov. 1929
,
Parry 839
(
K
); ibid.,
Oct. 1929
,
Parry 839
(
K
).
Mizoram
: Lushai Hills, 1929,
Parry 839
(
K
); ibid., 1934,
Parry
s.n. (
K
); Lushai Hills, Thenzawl,
May 1928
,
Parry 253a
(
K
).
Nagaland
: Naga Hills, Nichuguard,
17 Oct. 1885
,
Clarke 40854A
(
BM
); ibid.,
Clarke 40854D
(
K
); ibid.,
Clarke 40854G
(
K
).
Description
Rhizomatous, erect, monoecious herb, to ca
40 cm
high. Stem: stout, ca
5 mm
wide, glabrous, internodes
8–13 cm
long. Stipules: lanceolate, 12–15 ×
6–9 mm
, glabrous, semi persistent. Leaves: petiole
4–20 cm
long, glabrous; lamina ovate-orbicular to ovate, basifixed, base cordate with lobes overlapping or not, 8.5–25 ×
5–16 cm
, asymmetric, upper surface green, glabrous, underside green, glabrous or sparsely puberulent on the veins, venation palmate, midrib
6–18 cm
long; margin broadly dentate, appearing scalloped between main veins, with sparse hairs; apex acuminate. Inflorescence: cymose, axillary, few; peduncle glabrous, branching 2–3 times, primary
10–25 cm
, secondary
3–8 cm
, tertiary
3–5 mm
, with 2–
4 female
and 4–
6 male
flowers; bracts ovate to lanceolate, 10–20 ×
3–14 mm
, margin entire, deciduous. Male flower: pedicel ca
20 mm
long, glabrous; tepals 4; outer tepals broadly ovate to orbicular, 7–15 ×
4–9 mm
, pink to white, glabrous, margin entire; inner tepals ovate to lanceolate, 4–7 ×
2–6 mm
, pink to white, glabrous; androecium with 50–60 stamens, symmetric; filaments
1–3 mm
long, unequal, slightly fused at the base into a column; anther oblong elliptic,
1–2 mm
long, dehiscing through slits longer than half the length of the anther, not hooded, connective not extended. Female flower: pedicel
12–16 mm
long, glabrous, bracteoles absent; tepals 5, equal, ovate, outer tepals 10–12 ×
5–9 mm
, pink to white, glabrous, margin entire, inner tepals similar yet smaller; ovary 2-locular, placentae bifid; capsule oblong-ellipsoid,glabrous,with one long oblong wing and two short rounded wings;styles2,forked once and twisted twice, deciduous. Fruit: recurved; capsule oblong-ellipsoid, 14–18 ×
3–10mm
, glabrous; wings extending along the pedicel slightly, unequal; longest wing rounded oblong, 15–34 ×
8–12 mm
; shortest wing semi-circular, 3–7 ×
10–15 mm
.
Fig. 39.
Map showing the location of
B. megaptera
A.DC. specimens.
Distribution and phenology
Arunachal-Pradesh, Meghalaya, Mizoram and Nagaland; also in
Nepal
, Sikkim,
Bhutan
,
Bangladesh
and
Myanmar
;
500–1250 m
. Flowering: August to November; fruiting: October to March.
Conservation status
Least Concern.
Begonia megaptera
has an AOO of
40 km
2 and an EOO of
220,500 km
2 with ample
suitable habitat in the Himalayas and
Arakan
mountains. The populations in the Garo-Khasi Hills of
Meghalaya
are at risk due to deforestation. The species has been found near the Blue Mountain National Park of
Mizoram
, Nokrek National Park of
Meghalaya
and Namphada Reserve of Arunachal-Pradesh.
Remarks
Begonia megaptera
is superficially similar to
B. palmata
but can instantly be distinguished as it lacks the reddish brown silky indumentum. The rather poorly known
B. beddomei
also has similar scalloped leaves, but has female flowers with 8 tepals and hairs on the petioles and leaf lamina underside.