Transfer of Anoectochilus tetrapterus to Odontochilus (Orchidaceae) Avishek Bhattacharjee and H. J. Chowdhery* Central National Herbarium, Botanical Survey of India, Botanic Garden, Howrah 711 109, India. avibsi@rediffmail.com *Botanical Survey of India, Northern Circle, 192 Kaulagarh Road, Dehradun 248 195, India ABSTRACT. Anoectochilus tetrapterus Hook. f. (Or- chidaceae) is transferred to Odontochilus Blume as O. tetrapterus (Hook. f.) Av. Bhattacharjee & H. J. Chowdhery based on its morphological characteris- tics. An emended description and illustration are provided to facilitate identification of the species. Key words: Anoectochilus, Odontochilus, Orchid- aceae. Odontochilus Blume (Orchidaceae) is often includ- ed in Anoectochilus Blume because of its flowers with a similar lip and column structure. Blume (1858– 1859), Bentham (1883), Hooker (1890), and Pridgeon et al. (2003) treated the genera separately, whereas Lindley (1840), King and Pantling (1898), Pradhan (1976), Seidenfaden (1978), and Govaerts et al. (2010) treated the species of Odontochilus under Anoectochilus. Mabberley (2008) mentioned the occurrence of about 30 species of Anoectochilus and 45 species of Odontochilus (including Chamaegas- trodia Makino & F. Maek.) in the world. In India, Anoectochilus is represented by five species, whereas seven species of Odontochilus have been recorded from India during the present work. Pridgeon et al. (2003) recognized these two genera separately as classified within the subtribe Goodyerinae Klotzsch, tribe Cranichideae Endl. of the subfamily Orchid- oideae Lindl. J. D. Hooker (1890) described Anoectochilus tetrapterus Hook. f. based on C. B. Clarke’s collection from Manipur, India. Later, while treating the species, Hooker (1894: t. 2160) mentioned that ‘‘from the shortness of its spur this species of Anoectochilus approximates nearest of all to Odonto- chilus, and tends to invalidate the very artificial character by which these genera are kept apart— namely, that in the former genus the spur, even if reduced to a sac, is exposed, whereas in Odontochilus the sac is concealed by the bases of the lateral sepals, which hence form a mentum.’’ However, during revisionary studies of the subtribe Goodyerinae Klotzsch for the Flora of India project through the Botanical Survey of India, critical studies on both genera as found in India strongly suggest that they are quite distinct and should be recognized as separate. Anoectochilus tetrapterus can be identified by the presence of a 4-lobed, cruciform epichile and the floral column with two irregular membranous ap- pendages at the base. The taxon has green leaves with yellowish white veins (vs. reticulate in Anoectochilus); the hypochile is deeply saccate or shortly spurred (vs. long-spurred in Anoectochilus) and has elongate- oblong appendages (vs. irregularly peltate to car- unculate appendages); and the column has anterior stigma lobes (vs. lateral in Anoectochilus). The mesochile of A. tetrapterus is also very similar to a species of Odontochilus (O. crispus (Lindl.) Hook. f.) in being entire. Thus, A. tetrapterus is transferred to Odontochilus in the present treatment. It is worth mentioning that the illustration (t. 2160) of ‘‘Anoec- tochilus tetrapterus’’ in Icones Plantarum (1894) was inaccurately portrayed. Furthermore, the apical portion of the inflorescence (with two flowers) was later removed from the holotype (C. B. Clarke 42191), most likely so the flowers could be studied. Odontochilus tetrapterus (Hook. f.) Av. Bhattachar- jee & H. J. Chowdhery, comb. nov. Basionym: Anoectochilus tetrapterus Hook. f., Fl. Brit. India [J. D. Hooker] 6: 96. 1890. TYPE: India. Muneypoor [Manipur], Eerung, 2000 ft., 27 Nov. 1885, C. B. Clarke 42191 (holotype, K not seen, K photo). Figure 1. Terrestrial herb, 9–20 cm tall, rhizomatous; rhizome 4–6 cm, 2–3 mm diam., creeping, terete, rooting at nodes; roots 0.5–2 cm, pale yellowish brown, fleshy; stems 2–3 3 0.2–0.3 cm, ascending, glabrous, leafy. Leaves 3 or 4, 2.5–5.5 cm, scattered, glabrous, petiolate; petiole 0.4 –1 cm, sheathing at base; lamina 1.9–4.5 3 1.2–2.4 cm, obliquely ovate, dark velvety green, with 5 yellowish white veins, base obtuse to subtruncate, apex acute to acuminate. Inflorescence racemose, terminal, laxly 3- or 4-flowered, pubescent; peduncles 5–6 cm, with 2 sheathing bracts of 1.3–1.6 cm, lanceolate, long-acuminate, scarious, pubescent; rachis 2.5–5 cm. Floral bracts 1–1.4 3 0.25–0.4 cm, equal to or longer than ovary, lanceolate, acuminate, pubescent; flowers 1.7–2 cm; sepals free, pubescent outside, ciliate at apex, 1-veined; dorsal sepal 5–8 3 NOVON 21: 20–22. PUBLISHED ON 7APRIL 2011. doi: 10.3417/2008134