Volume 12 > Part 1 > Year 2011 > Page 27 > Orchidaceae > Brachycorythis

5. Brachycorythis neglecta H.A.Pedersen

Bot. J. Linn. Soc. 162: 71. 2010. Fig. 12; Plate I: 4.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Flowering shoots (16–)26.8–52 cm tall, measuring (6.6–)11–25.4 cm from node of the lowermost to node of the uppermost foliage leaf; internodes (1–)1.9–4.3 cm long on average. Foliage leaves (5–)6–11; longest leaf (ob)lanceolate to elliptic, acute to obtuse (to rounded), 3.6–5.5(–7.3) by (1.3–)1.6–2.8 cm; uppermost leaf 2.5–5.24(–6.8) cm long. Inflorescence 3- to 14-flowered; lowermost bract (2.4–)3.9–6.5 cm long; flowers white to dark purple or pale green, often with purple markings and/or with a bright yellow blotch at base of the labellum (colouration patterns very variable). Sepals obtuse; dorsal sepal oblong to (ovate-)lanceolate, (12.5–)14.2–20.9 by 3.9–6.5 mm; lateral sepals obliquely (ovate-)lanceolate. Petals nearly always free from column, obliquely (linear-)lanceolate, obtuse, 10–17.1 by 2.2–4.9 mm. Labellum subcircular (usually somewhat wider than long), rounded, often retuse (to emarginate), (14.1–)18.5–29 by (16.5–)22.2–31.2 mm; spur (conical-)cylindric, (7–)8–9.4(–11.9) mm long, (1.7–)2.1–3.4 times as long as vertical diameter of entrance. Column (1.9–)2.7–4.5 mm long to apex of auricles. Capsule not seen.

Thailand : NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai (1 km S of Chiang Rai – type: Garrett 303, holotype -BKF, isotypes -K L), Phayao, Nan, Lampang (Doi Khun Tan), Tak; NORTH-EASTERN: Sakon Nakhon (Nong Han); EASTERN: Ubon Ratchathani (Dom Pradit); PENINSULAR: (province unknown).

Distribution : Myanmar, Laos, Yunnan.

Ecology : Deciduous dipterocarp forests, mixed deciduous forests, seasonal evergreen forests, pine forests, bamboo thickets and exposed grassy areas on granite or limestone bedrock: 220–1,100 m alt. Flowering: June–August(–October).

Vernacular : Wan nang bua pong (ว่านนางบัวป้อง), ueang din fa man (เอื้องดินฟ้าม้าน)(Northern).

Notes: As demonstrated in a recent morphometric study (Pedersen 2010), the traditional circumscription of Brachycorythis henryi (Schltr.) Summerh. was too wide. Therefore, most of the material from Thailand and Myanmar previously assigned to the latter species is now referred to the newly described B. neglecta. The true B. henryi has its main distribution in Yunnan, but also extends into the Shan State of northern Myanmar. Seidenfaden (1977) recorded B. henryi from the same floristic regions as listed under Thailand above, as well as from central Thailand (based on two collections from Nakhon Nayok) and south-western Thailand (based on a collection from Kanchanaburi). The material from the latter regions belongs to B. helferi (Rchb.f.) Summerh.