Tridynamia bialata
Nomenclature
Accepted name/Authority/Place of publication:
Tridynamia bialata (Kerr) Staples, Thai Forest Bull., Bot. 32: 149. 2004.
Synonyms:
Porana bialata Kerr, Bull. Misc. Inform. 1941: 19. 1941. TYPE: Thailand. Prachuap [Khiri Khan]: Hui Sang, 1 Oct. 1930, Put 3166 (lectotype: BM; isotypes: A, ABD, BK, E, K, L).
Description
Habit:
Liana 2–20 m long; vegetative parts ferruginous; stem slender, basally woody; upper stems terete to angular, 2–3 mm diam., ± puberulent, glabrate, pith solid. Indumentum yellowish to rusty; hairs 2-armed, arms mostly erect or ascending.
Leaves:
Leaf petiole 1.4–4.5 cm long; blade broadly ovate to cordate, 5.5–10.2 by 4.5–7.8 cm, base cordate, apex acute to acuminate, rarely obtuse, apiculate, adaxially darker, pilose or subglabrous, abaxially paler, velutinous.
Inflorescences:
Inflorescence a raceme or panicle, 10–25 cm long; lower bracts foliaceous; petiole 4–10 mm; blade ovate to ovate-lanceolate, 2–2.5 by 0.9–1.5 cm, puberulent; upper bracts sessile, lanceolate to subulate, 1–3 mm long; pedicels filiform, 4–8 mm long, thickening but not lengthening in fruit; bracteoles linear-filiform, 3–4 mm long, persistent, to 5–7 mm in fruit.
Flowers:
Flowers odorless; buds narrowly fusiform, 7–9 mm long, apically acute or obtuse, puberulent. Sepals unequal, outer 2 narrowly elliptic-oblong, 3–4 mm long, basally tightly enveloping ovary, flaring and flat above, puberulent; inner 3 sepals shorter, ovate to lanceolate, < 1 mm long, glabrous or apically tufted with hairs. Corolla 8–15 by 7–11 mm, white, center yellowish, limb jagged, outside puberulent on midpetaline bands, inside glabrous. Stamens unequal, included; filaments 2–5 mm long, sparsely pilose basally; anthers < 1 mm long; pollen 3-colpate, oblate spheroidal, ca. 10 by 15–20 micrometer, surface psilate or minutely granulate. Pistil twice as long as calyx; ovary ovoid-globose, < 1 mm tall, attenuate into style, glabrous or apically hairy; ovules (1 or) 2; style filiform, 5–7 mm, glabrous; stigma globose, < 1 mm, entire to slightly emarginate.
Pollen:
Pollen 3-colpate, oblate spheroidal, ca. 10 by 15–20 micrometer, surface psilate or minutely granulate.
Fruits:
Fruiting calyx: outer 2 sepals linear-oblong, 3.5–5.4 by 0.7–1.1 cm, bases tightly surrounding utricle, constricted medially, flaring above, stiffly chartaceous, tan to brownish, subglabrous; inner 3 sepals unequal, ovate to lanceolate, 5–7 by 3–4 mm, membranous, outside puberulent apically, otherwise glabrous. Utricle ovoid-conical, 6–10 by 3–4 mm, apiculate by indurate style base, thinly chartaceous, tan to reddish brown, glabrous.
Seeds:
Seed ellipsoid-oblong, 4–5 by 2–3 mm, reddish brown to black, smooth, glabrous; hilum basal, circular, < 1 mm diam.
References:
Staples, G.W. 2006. Blumea 51: 403–491.
Biogeography, Ecology and Natural History
Distribution Map:
Distribution:
Thailand, Vietnam; probably also Laos and Cambodia (Map).
Ecology:
Forests, disturbed forests, scrub thickets, prairies, and near
villages, on clay soils and among rocks and crags. From 20–300 m elevation.
Phenology:
Months |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Flowering specimens |
1 |
2 |
1 |
1 |
||||||||
Fruiting specimens |
4 |
2 |
1 |
1 |
References:
Staples, G.W. 2006. Blumea 51: 403–491.
Other information
Common names and uses:
Tap tao (Thailand, Prachuap Khiri Khan); bónga yang Hröi (Vietnam, Jörai dialect).
Authorship for webpage
Editor:
George Staples, Esmond Er
Contributors: