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 annulata
K.Koch
[sect.
Platycentrum
]
Figs 10–11
Berliner Allgemeine Gartenzeitung
10: 76 (
Koch 1857
)
. –
Type
:
Bhutan
, Buxa,
Griffith 2505
(neo-: K000761427, here designated; isoneo-: BM).
Begonia griffithii
Hook.
,
Botanical Magazine
83: 4984 (
Hooker 1857
)
. –
Type
:
Bhutan
, Buxa,
Griffith 2505
(lecto-: K000761427, here designated; isolecto-: BM).
Citations in other publications
As
B. annulata
:
Koch (1858: 336
, 340),
Irmscher (1959: 191)
,
Grierson (1991: 244)
,
Kumar (2002: 643)
,
Uddin (2007: 593)
,
Hughes (2008: 7)
,
Dash (2010: 32)
,
Morris (2011b: 58)
; as
B. griffithii
: Regel (1857: 380)
, Regel (1859: 15), de
Candolle (1864: 350)
,
Clarke (1879: 647)
,
Clarke (1881: 119)
,
Clarke (1890: 25)
,
Burkill (1924: 288)
,
Irmscher (1959: 191)
,
Hara
et al.
(1979: 181)
,
Hynniewta (1994: 183)
.
Other material
INDIA
:
Arunachal-Pradesh
: Apa Tani valley,
16 Apr. 1965
,
Cox & Hutchinson 394
(
E
,
K
); Bapu Mountain,
Feb.–Mar. 1912
,
Burkill 36909
(n.v.); Bapu Mountain, Renging Camp,
Feb.–Mar. 1912
,
Burkill 36257
(n.v.); Bapu Mountain, Rotung,
Feb.–Mar. 1912
,
Burkill 38191
(n.v.); ibid.,
Feb.–Mar. 1912
,
Burkill 36299
(n.v.); Janakmukh,
Nov. 1911
–
Mar. 1912
,
Burkill 37275
(n.v.); Kekar Monying,
Nov. 1911
–
Mar. 1912
,
Burkill 37614
(n.v.); Lalik Valley,
Nov. 1911
–
Mar. 1912
,
Burkill 37338
(n.v.); Mariyang to Bhalukpung,
Rao
17795
(
ASSAM
n.v.); Zido,
Choudhery 18025
(
ARUN
n.v.).
Assam
:
16 Apr. 1965
,
Cox & Hutchinson 394
(
E
); Nilgiris, 1835,
Beddome 3195
(
BM
).
Mizoram
: Lungleh,
Gage 233
(
CAL
n.v.); ibid.,
Gage 232
(
CAL
n.v.,
MH
n.v.); Lushai Hills,
Parry 16
(
CAL
n.v.).
Nagaland
: Naga Hills, Kohima,
6 Jun. 1950
,
Chand 3176
(
MICH
); ibid.,
7 Jun. 1950
,
Chand 3180
(
MICH
); ibid.,
7 Nov. 1885
,
Clarke 41801A
(
K
); ibid.,
25 Jun. 1950
,
Koelz 25335
(
MICH
); ibid.,
12 Jan. 1951
,
Koelz 27247
(
MICH
); ibid.,
3 Jun. 1950
,
Koelz 25214
(
MICH
).
Fig. 10.
Map showing the location of
B. annulata
K.Koch
specimens.
Fig. 11.
Begonia annulata
K.Koch.
A–B
. Leaf.
C
. Male flower.
D–E
. Fruit. Photographs courtesy of Darrin Norton of a plant in cultivation in a private collection.
Description
Rhizomatous, erect, monoecious herb,
15–30 cm
high. Rhizome: ca
10 mm
wide, pubescent, internodes
7–15 mm
long. Stem: not always present,
3–5 mm
wide, densely pilose, internodes
2–3 cm
long. Stipules: lanceolate, 4–13 ×
2–6 mm
, tomentose on reverse, persistent. Leaves: petiole
3–12 cm
long, tomentose; lamina ovate, basifixed, base cordate with lobes almost not overlapping, 9–15 ×
5–10 cm
, asymmetric, upper surface dark green with a white/silver band running inside the margin, minutely tomentose-strigose or verrucose, underside red and green, strigose, denser on veins, venation palmate, midrib
8–11 cm
long; margin sinuate-undulate to shallow broad dentate, with hairs; apex acute. Inflorescence: cymose, axillary, few; peduncle pubescent, branching twice, primary
9–12 cm
long, secondary
9–11 mm
long, with 2–
4 female
and 2–
4 male
flowers; bracts lanceolate to ovate, 6–12 ×
2–5 mm
, margin hairy. Male flower: pedicel
10–33 mm
long, puberulous; tepals 4; outer tepals broadly obovate, 11–22 ×
10–16 mm
, white to pink, tomentose on reverse near base, margin entire; inner tepals oblong-obovate, 10–20 ×
5–10 mm
, white to pink; androecium with 60–90 stamens, symmetric; filaments
2 mm
long, subequal, fused at base into a short column; anther oblong elliptic,
1–2 mm
long, dehiscing through short slits near the tip, slightly hooded, connective not extended. Female flower: pedicel
25–30 mm
long, puberulous; bracteoles absent; tepals 4–5, equal, obovate-orbicular, outer tepals, 10–16 ×
5–11 mm
, white to pale pink, puberulous on reverse to glabrous, margin entire, inner tepals similar yet smaller; ovary 2-locular, placentae bifid, capsule ellipsoid, 4–7 ×
3–5 mm
, tomentose, with one long oblong-trianglar wing and two short oblong wings; styles 2, deeply forked once and twisted twice, caduceus. Fruit: recurved; capsule ellipsoid, 9–15 ×
6–10 mm
, puberulous to sparsely verrucose; wings extending along the pedicel slightly, unequal; longest rounded-oblong with a crenate tip, 10–16 ×
5–9 mm
; shortest crescent-shaped, 3–5 ×
7–14 mm
.
Distribution and phenology
Arunachal-Pradesh, Assam, Mizoram & Nagaland; also in
Nepal
, Sikkim,
Bhutan
,
Myanmar
and
Vietnam
;
600–2000 m
. Flowering: December to June; fruiting: from January to July.
Conservation status
Least Concern.Although
B. annulata
has a small AOO of
68 km
2
due to the small number of georeferenced specimens it has an EOO of
387,500 km
2
, with a range that takes in the Eastern Himalayas and the Arakan mountains. The species is also recorded near the Royal Manas and Black Mountain National Parks of Arunachal-Pradesh and the Annapurna conservation area in
Nepal
.
Remarks
This species shares similar leaf variegation with
B. rex
, but can easily be distinguished as
B. annulata
tends to have smaller leaves with a rough adaxial surface due to its strigose hairs;
B. rex
has leaves with a glabrous and smoothly bullate adaxial surface. Furthermore,
B. annulata
has hairs present on the peduncles, flowers and fruits, with
B. rex
being glabrous.
Begonia rex
has distinctive acuminate anther connectives, unlike the rounded connectives of
B. annulata
.
The
type
of
B. griffithii
Hook. (
Hooker 1857
) in Kew
has two barcodes, possibly due to confusion between Griffiths’ itinerary number (
2505
) and the herbarium number (
2571
) which was added later. These numbers refer to what is most probably a single gathering; there is also a second specimen in Kew with the same herbarium number (
2571
) but a different itinerary number of
1143
.
Koch (1858)
commented on Hooker at Kew naming
B. annulata
as
B. griffithii
. The protologue for
B. annulata
mentions a living plant sent from London to
Germany
originally collected by Griffith in
Bhutan
. There is, however, no mention of a herbarium specimen and none is to be found in the Berlin herbarium, where it would most likely have been stored. It seems that both Hooker and Koch independently examined living material derived from that collected by Griffith; they both also mention it being provided under the wrong name of
B. picta
. Hence using the same specimen as the
type
for both is appropriate.