Begonia annulata K.Koch, 1857

Camfield, Rebecca & Hughes, Mark, 2018, A revision and one new species of Begonia L. (Begoniaceae, Cucurbitales) in Northeast India, European Journal of Taxonomy 396, pp. 1-116 : 18-21

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).

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.