Calanthe pulchra (Blume) Lindl.

Kurzweil, Hubert, 2010, A precursory study of the Calanthe group (Orchidaceae) in Thailand, Adansonia (3) 32 (1), pp. 57-107 : 74-75

8. Calanthe pulchra (Blume) Lindl.

Genera and Species of Orchidaceous Plants: 250 (1833); Comber, Orchids of Java: 92 (1990); Seidenfaden & Wood, The Orchids of Peninsular Malaysia and Singapore: 173 (1992); Seidenfaden, Opera Botanica 124: 17 (1995); Comber, Orchids of Sumatra: 256 (2001). — Amblyglottis pulchra Blume, Bijdragen : 371 (1825). — Alismorkis pulchra (Blume) Kuntze, Revisio Generum Plantarum 2: 650 (1891). — Type: Indonesia, Java, Mt. Seribu, in forest, Blume s.n. (holo-,?BO). Calanthe curculigoides Lindl. , Genera and Species of Or-

chidaceous Plants: 251 (1833); Hooker, Flora of British

India 5: 854 (1890) . — Types: Penang (Peninsular

Malaysia) and Singapore, Wallich s.n., Wallich’s Cata-

logue 7340 (syn-, K-WALL!; isosyn-, P!). MATERIAL EXAMINED. — Peninsular, Nakhon Si Thammarat, Khao Luang, XI. [year not given], Jonganarok 632 ( BKF spirit). — Peninsular, Songkhla, Thorut 20 ( BCU spirit). — Peninsular, Yala, Banang Sata, 10.X.1991, Larsen et al. 42272 ( AAU, C spirit). — Peninsular, Yala, Hala Bala, 4.IX.2005, Poopath 378 ( BKF spirit). ILLUSTRATIONS. — Comber, Orchids of Java : pl. on page 92 (1990); Seidenfaden & Wood, The Orchids of Peninsular Malaysia and Singapore: fig. 74d-f, pl. 10a (1992); Comber, Orchids of Sumatra: pl. on page 256 (2001) .

DESCRIPTION

Terrestrial herbs, evergreen, glabrous, 40-60 cm tall. Basal sheaths 2, oblong-lanceolate, acute,

8-15 × 1.4-1.6 cm. Pseudobulbs inconspicuous and largely enclosed by leaf sheaths, close together, several-noded. Leaves 2-6, perennial, lanceolate-elliptic, acute or acuminate, (43-)64- 75 × 6-10.8 cm; with grooved petioles 21-24 cm long. Inflorescences erect, arising from the base of the leafy shoot, shorter than the leaves; peduncles 33-42 cm long; sterile bracts 3-6, erect or suberect, lanceolate-oblong, subacute, 2-5 cm long, the lower sheathing; raceme semi-dense or dense, 40- to 60-flowered; rachis 7-18 cm long; floral bracts caducous, lanceolate, acute, 3-4 cm long, concave. Flowers not opening widely, about 11 mm across, yellow-orange, lip often orange-red or red. Ovary indistinguishable from the pedicel, 10-15 mm long. Sepals elliptic-lanceolate, acuminate or apiculate, 3-veined; median sepal very concave, 13-14 × 4.5-6 mm; lateral sepals 12-13 × 3.9-4.6 mm. Petals obovate-lanceolate, acute, apiculate, 3- or 5-veined, 11-12 × 5.2-6.2 mm. Lip 3-lobed, 10-11 mm long, base completely united with the gynostemium, spurred; midlobe rectangular, apically obtuse, truncate or emarginate, apiculate, 3.1-4.3 × 2.2-2.7 mm; side lobes erect, rounded, 1.1-2 × 2-2.7 mm; callus as three prominent or obscure keels with the two outer swollen between the lip side lobes; spur cylindric, c. 10 mm long, apex hooked through 180 degrees or more. Gynostemium 4.5-7 mm long, rostellum long-beaked. Fruits not seen.

DISTRIBUTION AND PHENOLOGY

This species is widespread in western Malesia and reaches Peninsular Thailand. Also recorded in Indochina. The habitat ecology is not known in Thailand but elsewhere the species is found in rainforest in the lowlands and hills, from about 1000 to 1100 m. Flowering from September to November.

REMARKS

In Malesia there is a group of several species with medium-sized yellow or orange flowers and caducous floral bracts, among the species which range into Thailand including this species, Calanthe angustifolia and C. speciosa . Within the group C. pulchra is well characterised by its hooked spur apex.