e-Flora of Thailand

Volume 16 > Part 2 > Year 2023 > Page 510 > Zingiberaceae > Geostachys

2. Geostachys chayanii Mayoewfo-0000921596

Taiwania 55(1): 8. 2010.


Accepted Name : This is currently accepted.


Description : Perennial rhizomatous herb; rhizome raised above ground on stilt roots. Leafy shoots tufted, to 1.6 m tall with up to 3–4 basal, brown, bladeless sheaths; ligule oblong, 6–7 mm long, green or greenish brown, glabrous, apex acute; leaves 9–14, arranged in upper part of pseudostem; blades oblong-lanceolate, 30.1–37.2 by 2.3–4.7 cm, glabrous on both surfaces; base tapering towards petiole, apex acuminate, margin undulate; petiole 1.7–2.1 cm long. Inflorescences 1–few at base of pseudostem, 11.1–14.7 cm long, glabrous, slender; peduncle 2.3–4.7 cm long, glabrous, lower part covered with 6–10 reddish sheaths, oblong, 1.1–1.4 by 0.8–1.1 cm, apex obtuse or acute, upper part covered with 2–3 dry and membranous involucral bracts, oblong, 6.1–7.6 by 1.2–1.5 cm, apex mucronate, increasing in length upwards, basal part of inflorescence ascending, upper part (⅓ to ⅔) decurved (rarely ascending); rachis glabrous; cincinni 16–21, uniflorous (rarely biflorous), spreading evenly only on one side, pointing upward; cincinni stalks 0.7–1.1 cm long. Flowers only in part exserted from involucral bracts; primary bracts subtending cincinni oblong, 1.1–1.7 cm by ca 3 mm, apex acute, membranous, cauduous; bracteoles tubular, 1.5–2 cm by 5–7 mm, split by ca ¼, apex mucronate, glabrous; pedicel 3–4 mm long, glabrous. Flower: ovary oblong, ca 3 by 1.5–2 mm, glabrous; stigma obconical, ostiole horizontal; epigynous gland 1, apex shallowly emarginate; calyx 1.2–1.4 by 0.4–0.5 cm, split by ca ¼ on one side, apex mucronate; floral tube ca 1.1 cm long, dorsal corolla lobe ovate, 1.4–1.5 by ca 0.7 cm, apex hooded, basal part light reddish, upper part light cream, lateral corolla lobes oblong, 1.4–1.5 by 0.5–0.6 cm, apex obtuse to slightly hooded, basal part light reddish, upper part light cream; labellum oblong-obovate, 1.9–2 by 1.2–1.3 cm, with two small lateral lobes, minutely hairy above; stamen: filament 7–8 mm long, hairy below; anther ca 6 by 2 mm, opening by longitudinal slits, anther crest ca 2 mm long and wide, concave, apex round or acute, with or without two small side lobes. Fruit oblong to oblong-obovate, 1.4–1.5 cm by 5–7 mm, turning reddish brown when mature; seeds 2 in each locule, obovate, ca 6 by 4 mm, white with small thread-like aril.


Thailand : PENINSULAR: Nakhon Si Thammarat (Namtok Yong NP – type: Picheansoonthon 1021, holotype -BKF, isotypes -BK SING).


Distribution : Endemic.


Ecology : Evergreen hillside forests on humus-rich soil, on rock in shade, 890–1,200 m alt. Flowering: May; fruiting: June–October.


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