ספטמבר 24, 2022

One New Species and Four New Records of Begonia (Begoniaceae) from Bhutan

Begonia menchunaensis P.Gyeltshen & M.Hughes is described from the cool broadleaved forest of Punakha District in Bhutan. It is assigned to Begonia sect. Diploclinium because it has a tuberous habit and bifid placentae. Begonia menchunaensis is similar to B. picta Sm. but is distinguished from it by its moniliform tubers (vs single globose tubers); longer petioles up to 10–55 cm (vs 5–12(–20) cm), which are glabrous (vs sparsely puberulous); outer tepals in male and female flowers with an acute apex (vs rounded); and immature ovaries with simple red setose hairs (vs white fimbriate villose hairs). – Type: Bhutan, Punakha District, Toedpisa Block, Menchuna, 2284 m, 24 ix 2021, P. Gyeltshen 067-068 (holotype THIM [THIM17728], isotype THIM [THIM18604]).

Monoecious, tuberous herb, up to 25 cm tall. Tuber stout, moniliform, each section 1–3 cm in diameter, with numerous fibrous roots. Stem 1- or 2-branched, terete, glabrous, up to 20 cm long. Leaves: lamina symmetrical, broadly ovate to triangular-ovate, 15–35 × 10–26 cm, apex acuminate, base cordate, margin shallowly lobed, bidenticulate; adaxial surface green to olive green, white pilose, abaxial surface pale green to brownish green, venation palmate-pinnate, veins c.8, prominent beneath; petiole 10–55 cm long, up to 1.2 cm in diameter, fleshy, pale green to reddish brown, glabrous. Inflorescence terminal, a compressed cyme, appearing umbellate, bisexual, protandrous, 2- to 6-flowered; peduncle pilose when young, unbranched, 5–16 cm long, terete, pale green to lightly brownish red. Staminate flower: pedicels 2.5–4 cm long, erect or curved downwards, pilose, pale green to light brownish green; tepals 4, outer tepals broadly ovate to triangular-ovate, 1.7–2.1 × 1.5–2 cm, apex broadly acute, margin entire or serrate, outer surface sparely red setose, inner surface glabrous, pale pink to white; inner tepals elliptic, 1.2–1.6 × 0.5–1 cm, apex acute, margin entire, outer surface glabrous or a few red setose, whitish pink to white; androecium symmetrical, > 60 stamens, bright yellow; filaments clustered at the base on a column, free, unequal, 0.5–2 mm long; anthers obovate, 1–1.6 mm long, connective rounded, apex obtuse or truncate, dehiscing through lateral slits. Pistillate flower: pedicels 1.5–3 cm long, pilose, pale green or greenish red; ovary green, with 3 unequal wings, with simple red setose hairs, denser on the locular portion; 3-locular, placentation axillary, 2 branches per locule; tepals 5 (or 6), unequal, outer 3 tepals ovate to elliptic-ovate, 1.5–1.8 × 1–1.3 cm, apex acute, margin serrate, outer surface red setose, inner tepals 2 or 3, unequal, elliptic, 1–1.5 × 0.5–0.8 cm, apex acute, margin entire, glabrous, same colour as staminate flower; styles 3, fused at the base, dark yellow, deeply forked once and twisted twice. Capsule oblong-ellipsoid, 1–1.5 × 0.5–0.7 cm, green, with red setose hairs, wings slightly extending along the pedicel, unequal; dorsal wing, narrowly triangular, 3.5–4.6 × 1–1.5 cm, lateral 2 wings short triangular, 8–12 × 2–9 mm, sparsely red setose, warty.
It Flowers in September, fruiting from September to October.

פורסם ב ספטמבר 24, 2022 08:29 לפנה"צ <span class="translation_missing" title="translation missing: he.by">by</span> phubgyeltshen phubgyeltshen | תצפית 1 | 0 תגובות | הוספת תגובה

יולי 30, 2022

A new species of Begonia sect. Diploclinium, Begonia bhutanensis, from Bhutan

Begonia bhutanensis P.Gyeltshen & M.Hughes, sp. nov. (§ Diploclinium) Resembles Begonia rubella in habit, but differs in having fimbriate-laciniate bracts (not entire), rounded wings on the capsule (not elongate triangular), and a symmetric androecium with sub-uniformly sized anthers (not asymmetric with markedly heteromorphic anthers (Rajbhandary et al., 2011).

Plant monoecious, tuberous, herbaceous, 35–50 cm tall. Tuber subglobose, c. 1.9 × 1.6 cm, a creeping tuberous rhizome is also present, c. 4 × 0.8 cm, forming on an adventitious root from near the apex of the tuber. Stem erect or slightly pendent at distal portion, present during flowering, 44–45 cm long, red, glabrous, lowermost internodes 4–6 mm apart, unbranching, 2–4 leaves per stem. Stipules ovate, 1.5–2 × 0.8–1.2 cm, papery, keeled, apex cuspidate, margin entire, adaxial surface glabrous. Leaves alternate; petioles cylindrical, 3–12 cm long, 2–3 mm thick, reddish green, glabrous; lamina broadly ovate, 6–17 × 5- 16 cm, basifixed, base cordate, margin subentire and sparsely white ciliate, apex broadly acuminate, venation palmate-reticulate, veins 5–6; adaxial surface with sparsely scattered appressed white hairs c. 2 mm long; abaxial surface paler green, glabrous. Inflorescences terminal or axillary on stems with 4–5 internodes, bisexual, protandrous, dichasial cymes with 4–5 branches, erect to pendent; peduncles cylindrical, up to 26 cm long, reddish green or green, glabrous, bracts oblong, c. 5 × 2 mm, margin long fimbriate, apex obtuse, base truncate, glabrous. Staminate flower: pedicel c. 1–1.7 cm long, pale green, glabrous; tepals 4, pale pink to pink, margin entire; outer 2 orbicular, 7–9 × 6–8 mm, glabrous, apex and base rounded, margin entire, up to 8-veined; inner 2 narrowly obovate, 6–8 × 3–4 mm, glabrous, apex rounded, base obtuse; androecium loosely globose, stamens c. 20–25, 1–2 mm long, on a c. 2.5 mm column, anthers obovate-oblong, golden yellow, basal anthers sessile, central anthers on a c. 0.5 mm filament, apex rounded and slightly extended. Pistillate flower: pedicel up to 3 cm long, pale green to light pinkish-green, glabrous, tepals 3–4, pale pink to pink, glabrous, margin entire; outer 2 orbicular, 6–8 × 7 10 mm, orbicular, apex rounded, base truncate; inner 1–2 elliptic, 6–7 × 3–5 mm, base sub-obtuse; ovary green sometimes light pinkish on the wings, glabrous, with 3 subequal wings, 3 locules, placentation axillary, 2 branches per locule; styles 3, golden yellow, Y-shaped, c. 3 mm long, fused at base; stigma spiralled, spiral part papillose. Fruits green to pale pinkish green, trigonous-globose, c. 1.7 × 0.6 cm, glabrous; dorsal wing c. 1.7 × 1 cm, slightly falcate at apex, narrower towards the base, lateral wings c. 1.5 × 0.2–0.3 cm.

Phenology. Flowering and fruiting from August to September.

פורסם ב יולי 30, 2022 03:43 לפנה"צ <span class="translation_missing" title="translation missing: he.by">by</span> phubgyeltshen phubgyeltshen | 2 תצפיות | 0 תגובות | הוספת תגובה

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