4. Calanthe densiflora Lindley, Gen. Sp. Orchid. Pl. 250. 1833.
密花虾脊兰 mi hua xia ji lan
Alismorkis densiflora (Lindley) Kuntze; Calanthe kazuoi Yamamoto.
Plants 50-60 cm tall, with long creeping rhizome 3-4 mm in diam. Shoots spaced 5-6 cm apart along rhizome. Pseudobulbs small or inconspicuous, enclosed in basal sheaths of leaves. Leaves usually 3, basal, well developed at anthesis, not deciduous; blade lanceolate or narrowly elliptic, 35-40 × 2.3-6.5 cm, glabrous, apex acute; petiole-like base ca. 10 cm, articulate, enclosed by tubular sheaths and forming a slender pseudostem 10-16 cm. Scapes 1 or 2, arising from rhizome, erect, ca. 20 cm, 3-4 mm in diam., with 3-5 tubular sheaths toward base; rachis short, densely many flowered; floral bracts caducous, narrowly lanceolate, 1.5-3 cm, glabrous. Flowers arranged in a dense head, pale yellow, turning black when dried; pedicel and ovary ca. 20 mm, glabrous. Sepals similar, oblong, 13-14 × ca. 5 mm, 3-5-veined, apex aristate. Petals subspatulate, 13-14 × ca. 4 mm, 3-veined, apex acute; lip adnate to base of column wings, ovate-orbicular, 7-11 × 5-11 mm, 3-lobed above middle; lateral lobes ovate-triangular, ca. 5 × 3 mm, ca. 10 mm across their apices, apex obtuse; mid-lobe subsquare, ca. 5 × 4 mm, apex emarginate; disk with 2 lamellae; lamellae deltoid, ca. 2 × 3 mm; spur straight, cylindric, 12-16 × ca. 3 mm, apex obtuse. Column ± arcuate, ca. 12 mm, slender, base dilated; rostellum broadly ovate-triangular, ca. 1.2 mm, unlobed; anther cap beaked; pollinia obovoid, subequal in size, ca. 1.2 mm, with short caudicles. Capsule nearly pendulous, ellipsoid-globose, ca. 1.3 × 0.8 cm. Fl. Aug-Sep, fr. Oct. 2n = 40.
Broad-leaved and mixed forests, along streamsides and valleys; 1000-3000 m. Guangdong, Guangxi, Hainan, Sichuan, Taiwan, S and SE Xizang, NW and SE Yunnan [Bhutan, NE India, Vietnam].