Pecteilis radiata (Thunberg) Rafinesque Fl. Tellur. 2: 38. 1837.

狭叶白蝶兰 xia ye bai die lan

Orchis radiata Thunberg, Trans. Linn. Soc. 2: 326. 1794; Habenaria radiata (Thunberg) Sprengel; Hemihabenaria radiata (Thunberg) Finet; Plantaginorchis radiata (Thunberg) Szlachetko; Platanthera radiata (Thunberg) Lindley.

Plants slender, 18-37 cm tall. Tubers ellipsoid to subglobose, 0.8-2 × 0.5-1 cm. Stem slender, with 1 or 2 tubular sheaths at base, 3-5 spaced cauline leaves, and 1-3 sterile bracts above. Leaves linear to narrowly lanceolate, 4-10 × 0.3-0.8 cm, apex acuminate. Sterile bracts linear, 1.5-4 × 0.2-0.5 cm, apex acuminate. Rachis to 3.5 cm, 1- or 2-flowered; floral bracts ovate-lanceolate, 7-12 mm, shorter than ovary, apex acuminate. Flowers white, large; pedicel and ovary 10-15 mm, slightly ridged, glabrous. Dorsal sepal suberect, pale green, narrowly ovate, 7-10 × 2-3 mm, 5-7-veined, apex acute; lateral sepals spreading, pale green, narrowly ovate, slightly oblique, 8-10 × 2-4 mm, 5-7-veined, apex acute. Petals erect and loosely connivent with dorsal sepal, white, ovate, oblique, 10-12 × 3.5-6 mm, outer margin toothed to shallowly fimbriate, apex subacute; lip irregularly flabellate, 13-18 × 16-25 mm; lateral lobes obliquely flabellate, 8-12 × 6-10 mm, outer margins deeply fimbriate-laciniate; mid-lobe linear, 5-10 × 1-2 mm, slightly fleshy, entire, apex subobtuse; spur pendulous, straight to slightly curved forward, 25-40 × ca. 1.5 mm, slender, slightly dilated toward apex, apex obtuse. Fl. Jul-Aug. 2n = 32, 48.

Glades in forests; ca. 1500 m. W Henan [Japan].