Calanthe puberula Lindl.

Kurzweil, Hubert, 2010, A precursory study of the Calanthe group (Orchidaceae) in Thailand, Adansonia (3) 32 (1), pp. 57-107 : 81

14. Calanthe puberula Lindl.

Genera and Species of Orchidaceous Plants: 252 (1833) ; Hooker, Flora of British India 5: 848 (1890); Seidenfaden, Opera Botanica 114: 94 (1992); Pearce & Cribb, Flora of Bhutan 3 (3): 289 (2002); v. d. Bult, Natural History Bulletin of the Siam Society 53: 261 (2005); Chen et al., Flora of China, vol. 25: 298 (2009). — Alismorkis puberula (Lindl.) Kuntze, Revisio Generum Plantarum 2: 650 (1891). — Type: India / Bangladesh border, Sylhet, Wallich s.n., Wallich’s Catalogue 7342 (holo-, K-WALL).

MATERIAL EXAMINED. — Northern, Tak, Umphang, 24.IV.2001, v.d. Bult 412 ( CMU [Sc], CMU [Sc] spirit). — Northern, Phitsanulok, IX.[year not given], Suksathan 120 ( BCU spirit) .

ILLUSTRATIONS. — Seidenfaden, Opera Botanica 114: fig. 50a, b (1992).

DESCRIPTION

Terrestrial herbs, evergreen, 25-60 cm tall. Basal sheaths not seen. Pseudobulbs inconspicuous and largely enclosed by the leaves, ovoid, conical, 2-4 × c. 1.5 cm, close together, several-noded. Leaves 5-7, perennial, elliptic-oblong, acuminate, 6-25 × 3-7 cm; with grooved petioles 7-10 cm long. Inflorescences erect, arising from the base of the leafy shoot, pubescent or puberulous, greenish-purple; peduncles 17-25 cm long; sterile bracts erect or suberect, lanceolate, subacute, acuminate, 1.8-3.2 cm long, glabrous, not sheathing; raceme lax, few- to many-flowered; rachis 6-12 cm long; floral bracts persistent, lanceolate, acuminate, puberulous, 15- 25 × 3-5 mm, as long as or slightly shorter than the ovary plus the pedicel. Flowers to 30 mm across, lavender or light purple; all tepals puberulous on the outside. Ovary indistinguishable from the pedicel, linear, 15-30 mm long, puberulous. Sepals similar, spreading, ovate-lanceolate, acute, acuminate, 5-veined, 9-16 × 4-6.2 mm. Petals linear-oblong, acuminate, subacute or acute, 9-13 × 1-1.9 mm. Lip 3-lobed, 10-15 × 6-11 mm, base extensively united with the gynostemium, spurless; midlobe ovate, apiculate, 5-9.5 × 4.5-7.5 mm, front margins erose; side lobes oblong, obtuse, 4-6 × 3-3.5 mm, spreading and pointing forwards; disk with two calli at the base but without raised lamellae. Gynostemium stout, c. 4-6.5 × 3 mm. Fruits ellipsoid, c. 30 × 14 mm.

DISTRIBUTION AND PHENOLOGY

In Thailand known from only two collections made in the North. Generally widespread from N India to S China, Taiwan, Japan and Korea. Found in hill evergreen forest from 1300 to 2100 m. In Thailand found flowering in April and September.

REMARKS

Calanthe puberula was recorded in Thailand as recently as 2005. It is currently the only Thai species which does not have a lip spur and can therefore hardly be mistaken for any other. Also spurless is C. tricarinata Lindl. which is widespread from Pakistan to Myanmar and Japan but this species has not been recorded in Thailand as yet.