B. hinnamnoensis

Culture

Comments

Begonia hinnamnoensis is closely allied with B. cladotricha and B. gesneriifolia, as shown by characters of reniform lamina and pistillate flowers with 5-tepals. The basally-branched hair type of this species is the same as in B. cladotricha (Hughes, 2008b). The specific epithet hinnamnoensis refers to the type locality.

Endangered Status

IUCN category VUD1, known only from the type locality

Original Botanical Description or Link to

Two new species of Begonia L. (Begoniaceae) from central Laos Keooudone SOUVANNAKHOUMMANE, Soulivanh LANORSAVANH, Vichith LAMXAY: Begonia hinnamnoensis Souvann & Lanors., sp. nov. Som Koung Khan Khak [Bufo begonia] Sect. Diploclinium. Differs from the allied Begonia gesneriifolia Aver. in having a denser indumentum over all vegetative parts and fruit wings narrowly triangular (B. gesneriifolia has short scurfy hairs, sub-glabrous petioles, glabrous leaf lamina, inflorescenceand flowers, and fruit wings distinctly larger). Also differs from Begonia cladotricha M. Hughes in having a stout rhizome, upper surface of lamina bullate between veins giving a rugose appearance and pistillate flowers smaller fruit wings (B. cladotricha has tuberous rhizome, upper surface of lamina not bullate between veins and pistillate flowers larger fruit wings). − Type: Laos, Khammouan province, Boualapha district, Hin Nam No National Protected Area, 17°27'24.4"N 105°46'13.1"E, 240 m, 9 October 2017, Lamxay et al. HNN 227 (holo HNL, iso FOF, E, SING). Monoecious rhizomatous herb, 24–30 cm tall. Rhizome stout, c. 5–12 cm long, c. 5–8 mm in diam., erect near apex, c. 1.2 cm tall, with numerous fibrous roots. Leaves arranged in rosette-like cluster at the apex of rhizome; petiole 1.5–9 cm long, branched ginger hairs, fleshy, pale green to brown; lamina succulent, symmetrical, reniform, 2.4–6.8 × 3.2–9 cm, base shallowly cordate, apex rounded, margin crenate to undulate; adaxial surface lime green to olive green with sometime grey-white splotch, bullate between veins giving lamina a rugose appearance, abaxial surface pale green to brown, branched ginger hairs on both of surface; venation palmate, veins 6–9, prominent beneath. Stipules persistent, membranous, lanceolate to triangular, 8–22 × 4–12 mm, apex acuminate to caudate, margin entire, outside surface branched ginger hairs, inside surface glabrous, pink to lightly green. Inflorescences compound cymes arising from top of rhizome, branched up to 4 times, bisexual, 25–35 cm long, staminate flowers distal and pistillate flowers basal, protandrous; peduncles 23–30 cm long, terete, branched ginger hairs, lightly brown to red. Bracts ovate to triangular, 4–8 × 1.5–2.5 mm, apex acute, margin entire, branched ginger hairs on outside surface, pale green to brown. Staminate flowers: pedicels 5–9 mm long, erect or occasionally ascending, with sparse branched ginger hairs, red; tepals 4, outer pair ellipticobovate, 7–12 × 3–5 mm, apex obtuse to rounded, outside surface with sparse branched ginger hairs, inside surface glabrous, pale pink to white, inner pair narrowly elliptic, 3–4.5 × 1–1.8 mm, apex rounded, glabrous, pale pink to white; stamens c. 19, bright yellow, filaments clustered at the base, c. 0.3 mm long, free 0.5–1 mm long, anthers oblong-elliptic, 0.3–0.6 mm long, dehiscing by longitudinal slits near the tip. Pistillate flowers: pedicels 9–15 mm long, with branched ginger hairs, red; tepals 5, outer 2, oblanceolate-obovate, 6–11 × 4–8 mm, apex obtuse to rounded, outside branched ginger hairs, inner 3 unequal, obovate, 4–10 × 2.5–6 mm, apex rounded, glabrous, same colour as staminate flower; ovary lightly green to pale pink, with 3 subequal wings; 3-locular, placentation axillary, 2 branches per locule; styles 3, fused at the base, dark yellow, stigmatic band U-shaped and minutely papillose. Fruits capsules, subglobose, 4–7 × 3.5–6.8 mm; locules subglobose, 2.0– 2.5 × 2.2–2.7 mm, wings triangular, c. 5 mm long, 2–3 mm wide at base, with branched ginger hairs, pale green to pink, drying pale brown. Seeds numerous, ellipticoblong, 0.3–0.4 × c.0.1 mm, testa reticulate, brown. Distribution. Endemic to Khammouan province, Boualapha district, Hin Nam No National Protected Area, only know from type locality. Habitat and ecology. Occurring on limestone rock crevices in seasonally dry evergreen forest at 240 m elevation. Flowering September to October; fruiting October to January. Notes. Begonia hinnamnoensis is closely allied with B. cladotricha and B. gesneriifolia, as shown by characters of reniform lamina and pistillate flowers with 5-tepals. The basally-branched hair type of this species is the same as in B. cladotricha (Hughes, 2008b). The specific epithet hinnamnoensis refers to the type locality. Proposed IUCN category. VU D1. This new taxon is restricted to karst limestone and known only from the type locality in Hin Nam No National Protected Area.