2. Pomatocalpa undulatum (Lindley) J. J. Smith subsp. acuminatum (Rolfe) S. Watthana & S. W. Chung, Harvard Pap. Bot. 11: 249. 2007.
台湾鹿角兰 tai wan lu jiao lan
Cleisostoma acuminatum Rolfe, Bull. Misc. Inform. Kew 1913: 144. 1913; C. brachybotryum Hayata; Pomatocalpa acuminatum (Rolfe) Schlechter; P. brachybotryum (Hayata) Schlechter.
Stems 2-3 cm, 3-7-leaved. Leaf blade linear-lorate, 11-21 × 1.3-2.4 cm, leathery, conduplicate toward base, unequally bilobed. Inflorescences lateral, condensed-racemose, globose in outline, 1.3-4 cm, densely many flowered; floral bracts broadly triangular, 1.8-2.7 mm. Flowers ca. 8 mm in diam., fleshy, sepals and petals brownish yellow, sepals with 2 reddish brown transverse bands, petals with reddish brown patches near base, lip lateral lobes yellow, mid-lobe white, spur yellow; pedicel and ovary 4-8 mm. Sepals similar, suboblong, obtuse; dorsal sepal 3.7-4.5 × 1.5-2 mm; lateral sepals 3.5-4.2 × 2.1-2.4 mm. Petals incurved, falcate-oblong, 3.2-3.9 × ca. 1.3 mm, base contracted, apex obtuse; lip spurred at base, 3-lobed; lateral lobes erect, deltoid, 1.2-1.3 × 0.4-0.5 mm; mid-lobe broadly triangular or suborbicular, 2.2-3 × 2.2-3.3 mm, base with 2 keels, apex subacute; spur saccate, dorsiventrally compressed, 3.3-4 × 2-3 mm, inside with an appendage on back wall covering its entrance. Column 0.9-1.2 mm; anther cap beaked at apex. Fl. Mar-Apr.
● Epiphytic on tree trunks in forests; ca. 800 m. S Taiwan.
Pomatocalpa undulatum subsp. undulatum, from Bangladesh and NE India, is distinguished by the floral bracts, which are 0.4-0.5 mm, and the relatively small flowers with dorsal sepal ca. 3.5 mm and spur 1.8-2.3 mm.