9. Hornstedtia Retzius, Observ. Bot. 6: 18. 1791.
大豆蔻属 da dou kou shu
Rhizomes creeping, branched, woody. Pseudostems robust. Leaves sessile or petiolate; ligule conspicuous; leaf blade lanceolate. Inflorescence arising from rhizomes near base of pseudostems, often ca. 1/2 embedded in ground, an ovoid or fusiform spike; peduncle usually short, clothed with 2-ranked, scalelike sheaths; bracts densely imbricate, outer ones leathery, sterile, inner ones membranous, slimy, 1-flowered; bracteoles open, not tubular. Calyx tubular, widened distally, split on 1 side, apex 3-toothed or 2-lobed. Corolla tube slender, apex usually incurved at a right angle; lobes 3, central one erect, hooded, lateral ones spreading, partly adnate to labellum. Lateral staminodes reduced to small teeth at base of labellum or absent. Labellum equaling corolla lobes, narrow, concave, and fleshy, triangular, ovate, or hastate when flattened, base auriculate, apex oblong-rounded. Filament short or absent; connective appendage orbicular or absent. Ovary oblong, 3-loculed. Style slender; stigma funnelform. Stylodes 2--8, united or free. Capsule subcylindric or nearly 3-angled, smooth; pericarp tough, splitting irregularly near base. Seeds black, many angled, base covered with white aril.
About 60 species: tropical Asia; two species (endemic) in China.
Hornstedtia arunachalensis S. Tripathi & V. Prakash (Nordic J. Bot. 19: 329. 1999) was recently described from extreme SE Xizang. It was compared with the Malesian species, H. scyphifera (J. König) Steudel, from which it differs in having fusiform, closed-mouthed inflorescences, white corolla lobes, and a whitish labellum without lateral auricles. No specimens have been seen by the present authors. From the description and illustration, H. arunachalensis seems similar to H. tibetica, and the two may perhaps be conspecific.
