台湾芋兰 tai wan yu lan

Tuber whitish, subglobose, 5-15 mm in diam., 3- or 4-noded. Leaf abaxially green with purple venation, adaxially green with irregular silvery-white mottling, 5- or 7-sided to cordate, 3-4.5 × 3.5-4.5 cm, with 5 or 7 main veins, slightly fleshy, glabrous, base deeply cordate, apex acute or obtuse; petiole-like stalk erect, 2-5 cm, with 1 or 2 short tubular sheaths near base. Inflorescence 7-15 cm, 1-flowered; peduncle brown to greenish brown with purple flecks, with 2 or 3 tubular sheaths, elongating in fruit; sheaths brown to greenish brown with purple flecks, 1-2 cm, apex acute or acuminate; floral bract ovate-lanceolate, 4-7 × 1-2 mm, apex acute. Flower nodding, resupinate, opening widely or not, 16-25 mm in diam.; pedicel and ovary brown or greenish brown with purple flecks, 6-10 mm. Sepals brown to greenish brown with purple flecks, lanceolate, 18-22 × 2.2-3 mm, apex acute or acuminate. Petals brown to greenish brown with purple flecks, lanceolate, 16-20 × 1.5-2 mm, apex acuminate; lip white with purplish magenta spots and blotches, oblong or oblanceolate, 14-20 × 4.5-8 mm, spurless, 3-lobed near middle; lateral lobes erect and loosely embracing column, triangular, ca. 4 × 1-2 mm, apices acute; mid-lobe narrowly obovate to elliptic, 8-10 × 4-6 mm, apex acute; disk papillose, densely pubescent-lanate between lateral lobes, with a central longitudinal ridge extending from near base of lip almost to apex of mid-lobe. Column white, 4-6.5 mm, with a cluster of hairs below stigma, apex dilated; pollinia enclosed within clinandrium; stigma shield-shaped; rostellum large. Fl. Mar.

● Evergreen forests; 500-2000 m. Taiwan.

This species has been considered conspecific with the Japanese Nervilia nipponica Makino by some authors (e.g., see T. P. Lin, Native Orchids Taiwan 3: 174. 1987; H. J. Su, Fl. Taiwan, ed. 2, 5: 978-979. 2000). However, N. nipponica has a uniformly green (non-mottled), membranous leaf, smaller floral parts, a semipeloric perianth in which the petals bear patches of papillae (as on the lip), and a column that lacks a rostellum. Accordingly, N. taiwaniana and N. nipponica should be treated as separate species. A recent collection from Yunnan that was referred to N. nipponica (G. W. Hu et al., Acta Bot. Yunnan. 30: 146. 2008) does not match authentic material of that species from Japan and is distinct also from N. taiwaniana. Further investigation may reveal the Yunnan entity to represent a new species.