Calanthe labrosa

Kurzweil, Hubert, 2010, A precursory study of the Calanthe group (Orchidaceae) in Thailand, Adansonia (3) 32 (1), pp. 57-107 : 72-74

6. Calanthe labrosa (Rchb.f.) Rchb.f.

Gardeners’ Chronicle, n.s., 1883: 44 (1883); Hooker, Flora of British India 5: 856 (1890); Seidenfaden, Dansk Botanisk Arkiv 29: 41 (1975); Seidenfaden, Opera Botanica 124: 15 (1995); Chen et al., Flora of China, vol. 25: 309 (2009). — Limatodis labrosa Rchb. f., Gardeners’ Chronicle, n.s., 11: 202 (1879). — Calanthidium labrosum (Rchb.f.) Pfitzer in Engler & Prantl (eds), Die Natürlichen Pflanzenfamilien 2 (6): 153 (1888). — Alismorkis labrosa (Rchb.f.) Kuntze, Revisio Generum Plantarum 2: 650 (1891). — Type: Myanmar, Moulmein, Veitch’s collectors (not known).

MATERIAL EXAMINED. — Northern, Chiang Mai, Doi Chiang Dao, 31.I.1996, Maxwell 96-149 ( BKF, CMU [Sc], CMU [Sc] spirit); 11.XII.1983, Rasmussen sub Seidenfaden & Smitinand 9163 (C spirit). —? Northern , Chiang Mai, 2.XI.[year not given], Thaithong 519 ( BCU spirit). — Northern , Chiang Rai, Doi Tung , 30.XI.2005, Maxwell 05-681 ( CMU [Sc], CMU [Sc] spirit); 20.X.2006, Palee 1041 ( CMU [Sc], CMU [Sc] spirit). — North-Eastern , Khon Kaen, Phu Khieo , 7.XI.1984, Murata et al. T 41675 ( BKF, C spirit, L). — Peninsular, Ranong, Khao PoTa Luang Kaew, 6.XII.1994, BCU Herb. Tr. 1041 ( BCU spirit). —?Without locality, without collector (K spirit 51295) .

ILLUSTRATIONS. — Seidenfaden, Dansk Botanisk Arkiv 29: fig. 15a, b (1975); Seidenfaden, Opera Botanica 124: fig. 6a-e (1995).

DESCRIPTION

Lithophytic, terrestrial or very rarely epiphytic herbs, deciduous, 25-30 cm tall. Basal sheaths not seen. Pseudobulbs prominent, ovoid, conical, 2-8 × 1.5-4 cm, close together, made up of several internodes with the largest part derived from a single node, covered by greyish-silvery leaf sheaths, glabrous. Leaves 1-3, annual and usually not present at the flowering time, lanceolate-oblong, acute or acuminate, 25-44 × 8.9-10.4 cm, glabrous; petioles 10-12 cm long. Inflorescences arising from the basal part of the pseudobulb, erect at the base and nodding in the apical part, softly pubescent; sterile bracts 4-7, erect or suberect, scattered along the flowering stem and a few clustered at its base, lanceolate-oblong, acute or acuminate, 1-3 cm long, pubescent, the lower sheathing; occasionally decayed at the flowering time and only their scars visible; raceme lax or semi-dense, 3- to 10-flowered; floral bracts persistent, ovate-lanceolate, acuminate, 10-20 × 7-14.2 mm, much shorter than the pedicel plus the ovary, pubescent. Flowers 20-25 mm across, with violet or light violet sepals, petals and lip epichile, lip hypochile white, spur pale pink, also reported as white-pink and fading yellow, lip sometimes with dark pink dots, gynostemium pink, violet or orange, pollinia whitish. Ovary indistinguishable from the pedicel, 22-30(-40) mm long, densely pubescent. Sepals ovate-lanceolate, aristateacuminate, 3- or 5-veined, 9-14 × 3-5.8(-6.8) mm, pubescent on the outside. Petals ovate-elliptic, subacute, 5-veined, 9.5-15 × 4-5.5 mm, glabrous. Lip unlobed, rounded triangular, 11-15 × 13-19 mm, base not united with the gynostemium, spurred, edge very wavy; with three fleshy keels at the base which normally become lower towards the lip apex but are sometimes developed into a lamella, rarely the ridges very obscure; spur cylindric, 22- 29 mm long, pubescent, straight, parallel to the ovary. Gynostemium 4-6.5 mm long, glabrous or glandular-hairy, straight or slightly curved, with a 3-3.5 mm long column-foot. Fruits not seen.

DISTRIBUTION AND PHENOLOGY

In Thailand known from a few widely scattered localities in the North, North-East and the Peninsula.Also recorded in Myanmar and S China.Mostly terrestrial or epilithic on limestone in deciduous and evergreen forest with bamboo, from about 850 to 1950 m. Flowering mainly from October to January.

REMARKS

This species is very similar to Calanthe cardioglossa but has an undivided lip. It has only recently been reported in Thailand ( Seidenfaden 1995). Seidenfaden also commented on a specimen from Kanchanaburi Province (Sukhakul sub Seidenfaden & Smitinand 9580) which differs in its apically incised lip, and a formal separation giving it varietal status was considered. However, the lip base of the speci-

The Calanthe group ( Orchidaceae ) in Thailand

men is extensively fused with the gynostemium, and it appears that the specimen is altogether different from C. labrosa as had been earlier suggested by Seidenfaden himself (notes in his working files in Copenhagen). In the present paper it is listed as “ Calanthe indet.” (see below).

7. Calanthe rosea (Lindl.) Benth. ( Fig. 4 )

Botanical Journal of the Linnean Society 18: 309 (1881); Hooker, Flora of British India 5: 856 (1890); Seidenfaden & Smitinand, The Orchids of Thailand – A Preliminary List, part III:333 (1961); Seidenfaden & Smitinand, The Orchids of Thailand – A Preliminary List, part IV, 2: 792 (1965); Seidenfaden, Dansk Botanisk Arkiv 29: 39 (1975).— Limatodis rosea Lindl. , Paxton’s Flower Garden 3: 35 (1852). — Alismorkis rosea (Lindl.) Kuntze, Revisio Generum Plantarum 2: 650 (1891). — Type: Myanmar, Moulmein, Province of Martaban, Lobb s.n. (not known).

MATERIAL EXAMINED. — Northern, Nan, Sakoen National Park, 30.XI.2006, Watthana 2190 ( QBG, QBG spirit). — Northern, Lampang, Jae Sawn National Park , 6.XII.1995, Maxwell 95-1294 ( BKF, CMU [Sc], CMU [Sc] spirit, L). — Northern, Tak, Doi Mussoe, 6.XII.1960, Smitinand 7050 ( BKF, C, C spirit). — North-Eastern, Phetchabun, Thung Salaeng Luang, 21.XII.1964, Seidenfaden & Smitinand 5372 (C spirit). — South-Western, Uthai Thani, Huai Ka Kaeng Game Reserve , 20.II.1970, v. Beusekom & Santisuk 2862 ( AAU, BKF, C spirit, E, L). — South-Western, Sai Yok, Thai-Danish Botanical Studies 9208 (C spirit); 23.XII.1931, Kerr s.n. (K H2006/01478-261); 4.XII.1961, Larsen 8490 (C, E, SING); 31.XII.1963, Seidenfaden & Smitinand 4315 (C spirit). — South-Western, Kanchanaburi, Ta Kanum, 21.I.1926, Kerr 0262 ( BK, C, K). — South-Western, Thong Pha Phum District , 29.XI.1982, Koyama et al. 30453 ( BKF). — South-Western, Kanchanaburi, Sangkhlaburi, 14.I.1994, Maxwell 94-39 ( CMU [Sc], CMU [Sc] spirit, L). — South-Western, Kanchanaburi, Ban Mae Numb Noi, 30.XII.1961, Phengklai 355 ( BKF). — South-Western, Kanchanaburi, Huay Bankan, 8.XI.1971, v. Beusekom et al. 3517 ( BKF, C, K, L). — South-Western, Phetchaburi, Kaeng Kra Chan National Park , 4.XII.1993, Larsen et al. 45025 ( AAU). — South-Eastern, Prachin Buri, IX. 1987, Thaithong 210 ( BCU, BCU spirit). — Without locality, 26.XI.1997, Nanakorn et al. 9978 ( QBG, QBG spirit) .

ILLUSTRATIONS. — Seidenfaden & Smitinand, The Orchids of Thailand – A Preliminary List, part III: fig. 254 (1961); Seidenfaden, Dansk Botanisk Arkiv 29: fig. 14 (1975).

DESCRIPTION

Lithophytic or very rarely epiphytic herbs, deciduous, 22-55(-66) cm tall. Basal sheaths not seen. Pseudobulbs prominent, ovoid to oblong, 2.4-14 × 1-3.5 cm, close together, several-noded with the largest part made up of a single internode, covered by greyish-silvery leaf sheaths, glabrous, sometimes narrowed in the middle. Leaves to 4, annual and usually not present at the flowering time, broadly elliptic-oblong, acute, 37-40 × 5.8-11 cm, glabrous; petioles 3.5-6 cm long. Inflorescences arising from the base or middle of the pseudobulb, erect at the base, sometimes slightly nodding in the apical part, softly pubescent; peduncles to 40 cm long; sterile bracts 4-8, erect or suberect, scattered along the flowering stem and a few clustered at its base, lanceolate-oblong, acute or acuminate, 1-6 cm long, pubescent, sheathing; partly decayed at the flowering time; raceme lax or semi-dense, 5- to many-flowered; rachis 10-20 cm long; floral bracts persistent,membranous, ovate-lanceolate, acuminate or long-acuminate, 12-25(-33) × 3-8 mm, pubescent. Flowers pink or pale pink, lip often darker, hypochile sometimes white. Ovary indistinguishable from the pedicel, 20-29 mm long, pubescent.Sepals ovate-lanceolate, acute, apiculate, 3- or 5-veined, pubescent on the outside; median sepal (15-)19- 30 × 5-8 mm; lateral sepals oblique, (16-)18-30 × 3.7-7 mm. Petals obovate-elliptic, slightly wider than the sepals, shortly acuminate, 5- or 3-veined, (16-)20-30 × (4-)5.3-8.5(-9) mm, largely glabrous but sometimes with scattered hairs near the apex. Lip unlobed, rounded rectangular, (17-)23.5-35 × (10-) 12.5-16 mm, not united with the gynostemium, apex emarginate, truncate or sometimes slightly apiculate, hypochile rolled around the gynostemium, spurred, without ornaments; spur cylindric, pubescent, 11-16 mm long.Gynostemium 3.5-6 mm long, pubescent. Fruits not seen.

DISTRIBUTION AND PHENOLOGY

In Thailand frequent in the North and South-West; in addition one record each in the North-East and

South-East. Also found in Myanmar. Locally common on limestone rocks in mixed dry deciduous forest or dry evergreen forest or scrub, also in bamboo forest, from about 200 to 900 m. Flowering mainly from November to January .

REMARKS

Calanthe rosea is one of the most attractive Thai calanthes, easily distinguished from all others by the large flowers with an unlobed rounded rectangular lip. The species is commonly found growing on limestone rocks, but the specimen Kerr 0262 was found growing as an epiphyte.

The collection v. Beusekom & Santisuk 2862 differs from the typical Calanthe rosea in its considerably longer floral bracts (measuring 30-33 mm).

Figures

FIG. 4. — Calanthe rosea (Lindl.) Benth., flower. Thai-Danish Botanical Studies 9208. Reproduced with permission from the University of Copenhagen, drawn by Kai Olsen. Scale bar: 1 cm.