Volume 16 > Part 2 > Year 2023 > Page 734 > Zingiberaceae > Zingiber

50. Zingiber sirindhorniae Triboun & Keerat.wfo-0001426480

Thailand Nat. Hist. Mus. J. 10(1): 2. 2016. Fig. 51, Plate LXXXVII: E.

Accepted Name : This is currently accepted.

Description : Rhizomatous, lithophytic herb 40–70 cm tall, shoots 3–15, loosely clumping; rhizome sympodial, rounded or nearly so, 1–1.4 cm diam., brown outside, yellowish brown inside, with the scent of culinary ginger; storage roots 2–6, cylindrical, 3–6 cm long, ca 7 mm diam. Leaf sheaths slender, 2–4 mm diam., bladeless sheaths 3–5; ligule bilobed, lobes 3–5 mm, red; blades 5–12, oblong, 8–14 by 3.6–4.5 cm, distichously arranged, glabrous on both surfaces, base cuneate, apex acuminate; petiole 3–6 cm long, swollen, green. Inflorescence terminal; peduncle 1–2 cm long; spike erect, 5.5–7.5 by 1 cm, with 6–8 bracts, each with a single flower; bracts 2.2–2.6 by 0.6 cm, green or maroonish red, apex acute, sparsely hairy. Flower: ovary ca 3 by 3 mm, sparsely hairy, ovules 3–5 per locule; style slender, extending beyond anther and anther crest; stigma ciliate; epigynous glands ca 3 mm long; calyx tubular, 1.2–1.4 by 0.3 cm, lobes 7–9 mm, apex tridentate; floral tube white, ca 1.5 cm long, dorsal corolla lobe 1.7–2 by 0.5–0.6 cm, white, lateral corolla lobes 1.7–1.9 by ca 0.4 cm, white; labellum dark purple in outer half and at edge, base and middle of lower half white, conspicuously trilobed, ca 2 cm long, midlobe orbicular 1–1.3 cm wide, apex shallowly emarginate, side lobes subglobose, ca 5 mm wide, apex rounded; stamen: filament short; anther cream-white with red or maroonish dots or mottled, ca 10 by 3 mm, anther crest dark maroonish, ca 1 cm long. Fruit ellipsoid, ca 2 by 0.4 cm; seeds 1–3, black, ellipsoid, ca 2 by 2 mm; aril white.

Thailand : NORTH-EASTERN: Loei (Pha Khao – type: Triboun et al. 4060, holotype -BK, isotype -BKF).

Distribution : Endemic.

Ecology : Partially shaded dry evergreen forests on limestone hills, 350–450 m alt. Flowering: June–August; fruiting: July–October.

Vernacular : Aiyarit (ไอยริศ).

Notes: Another four Thai species of Zingiber produce terminal inflorescences; the inflorescence is always terminal in Z. pellitum Gagnep. and Z. gramineum Blume while Z. barbatum Wall. and Z. junceum Gagnep. occasionally produce a terminal inflorescence.