Cypripedium japonicum var. formosanum (Hayata) S. S. Ying
Plants 30-40 cm tall. Rhizomes stout, branching. Stems erect, 15-25 cm long, 7-9 mm thick, with few tubular sheaths at base, nearly glabrous. Leaves 2, near apex of stem, opposite, sessile, ovate-orbic-ular or orbicular-rhombic, 10-15 cm long, 8-12 cm wide, apex rounded, apiculate, base truncate, membranaceous, plicate, nearly entire or margins erose and ciliate, minutely hirsute on both surfaces, many nerved. Peduncle 8-12 cm long, nearly glabrous; bracts ovate-lanceolate, 3-4 cm long, 1 cm wide; pedicel and ovary pendulous, 3-4 cm long, minutely pubescent. Flowers solitary, whitish to pale pink, with red lines and spots, ca. 7-9 cm in diam.; dorsal sepal ovate to ovate-lanceolate, 4.5-6 cm long, 2-2.5 cm wide apex, acute or acuminate, contracted at base; synsepal ovate, 5 cm long, 2.5-3 cm wide, shortly bifid at apex; petals lanceolate, 5-6 cm long, 1.2-1.5 cm wide, apex acute, densely red spotted and hirsute near base; lip sac whitish, with red or purple dots and stripes, ovoid or ellipsoid, 4.5-6 mm long, 4 cm wide, 3 cm tall, margins of opening deeply infolded, barbate inside at base of sac; column ca. 2 cm long, 5 mm thick, barbate at ventral base; anther ovoid or globose, 5 mm across, filament short and thick; staminode short stalked, reddish, ovate-triangular, 7-8 mm long; stigma thick, whitish, solid cymbiform, 1 cm long, protruding beyond staminode. Capsules fusiform, 4-5 cm long.
ILAN: Chungyangchienshan, Su 745. NANTOU: Tsuifong, Hayata s. n. Apr 1916; Meifong, Su & Wu 9550. HUALIEN: Chingshuishan, Su 9496; Lolochi, Su 8175.
Endemic, forests in central range, 1,500-3,000 m.