Volume 16 > Part 2 > Year 2023 > Page 664 > Zingiberaceae > Rhynchanthus

1. Rhynchanthus bluthianus Wittm.wfo-0000513261

Gartenflora 48: 38. 1899; Schumann, Pflanzenr. IV, 46 (Heft 20): 377. 1904; Muangyen et al., Thai J. Bot. 7(1): 79. 2015. Fig. 41 A–C, Plate LXXVIII: A.

Accepted Name : This is currently accepted.

Description : Epiphytic herb; rhizome conical, to 3 cm long, 1–1.3 cm diam. Leafy shoot 10–42 cm long; bladeless sheaths 1–2, glabrous; leaf-sheaths red, glabrous; ligule 1–3 mm long, glabrous, translucent, apex truncate to slightly emarginate; blades 4–6, narrowly lanceolate, oblong, to narrowly elliptic, (6–)9–25.7 by 1–4.4 cm, pubescent along midrib, base obliquely cuneate to attenuate, apex acuminate-caudate; sessile or with petiole 0.3–1 cm long. Inflorescence a terminal spike, (1–)5–8(–14)-flowered, 8–17 cm long; peduncle 1–9 cm long, glabrous; bracts secund, red, ovate-lanceolate, 2.2–4.2 by 0.7–1.5 cm, glabrous, apex acute, 1-flowered; bracteoles translucent red, lower half tubular, upper half narrowly triangular, ca 9 mm long, apex acute to rounded. Flowers secund, 5–6.5 cm long, white or pinkish to purplish white; ovary ca 2 mm diam., glabrous; style filiform, ca 6 mm long; stigma cup-shaped; epigynous glands 2, cylindrical, ca 2 by 1 mm; calyx translucent red, tubular, 2.5–2.7 cm long, apex 2–3-toothed, unilaterally split, ca half of its length; corolla white, floral tube 7–8 mm long, glabrous, lobes erect and closely appressed, dorsal lobe long-navicular, ca 3.8 by 1 cm, apex acute, lateral lobes oblanceolate to narrowly oblanceolate, 3.5–3.7 by 0.5–0.7 cm, apex acute; lateral staminodes and labellum reduced, mostly connate to filament forming a staminodal tube, 3–3.2 cm long, apex divided into 2 small, dark purple, truncate lobes, ca 2 mm wide; stamen white to purplish white; filament long-navicular, free part above staminodal tube 2.5–2.7 cm long, glabrescent to densely pubescent on both surfaces; anther oblong, 6–7 mm long, white to cream, connective densely pubescent. Fruit ovoid, 1.5–2.4 by 0.6–0.8 cm, light green; seeds cylindrical, 2–3 mm long, slightly curved; aril translucent white.

Thailand : NORTHERN: Mae Hong Son (Sop Moei), Chiang Mai (Omkoi).

Distribution : Myanmar (type).

Ecology : Epiphyte on trees in lower montane forests, rather rare, ca 1,200 m alt.

Vernacular : La-kuei-kho (ละกึยค่อ)(Karen, Chiang Mai).

Notes: Rhynchanthus bluthianus is easily distinguished from R. longiflorus by its rhizome without minty scent, smooth leaf sheaths and white to pinkish white flowers.