Description from Flora of China
Callista falconeri (Hooker) Kuntze; Dendrobium erythroglossum Hayata.
Stems pendulous, cylindric, 30-40 cm or longer, slender, 2-3 mm in diam., fleshy, many branched, often swollen at branched nodes and moniliform, internodes often dilated above middle, to 3.5 cm on main stem, to 1 cm on branches, brownish yellow when dry, sometimes tinged with dirty black. Leaves often 2-5, alternate on upper part of branches, narrowly lanceolate, 5-7 × 0.3-0.7(or more) cm, leathery, base sheathing, apex obtuse or acute and slightly hooked; leaf sheath usually pale pink, tubular, papery. Inflorescences lateral, 1-flowered from each peduncle (occasionally a second peduncle arising creating a 2-flowered inflorescence); peduncle 5-15 mm, slender; basal sheaths 1 or 2, tubular, membranous; floral bracts white, ovate, 3-4 mm, membranous. Pedicel green; ovary yellowish green with purplish red spots, ca. 1.5 cm, slender. Flowers spreading, large, thinly textured; sepals pale purple or red with deep purple tip, petals white with purple apex, lip white with purple tip, yellow on both sides at base, disk with a deep purple blotch, column foot pale red, anther cap creamy white. Dorsal sepal ovate-lanceolate, 30-36 × 7-8(or more) mm, 8- or 9-veined, base slightly contracted, apex acuminate; lateral sepals ovate-lanceolate, ca. as large as dorsal sepal, 8- or 9-veined, base oblique, apex acuminate; mentum subglobose, ca. 6 mm. Petals ovate-rhombic, 29-33 × 14-16 mm, main veins 5 or 6, secondary veins many, base cuneate, apex subacute; lip ovate-rhombic, ca. as long as petals but much wider, adaxially densely barbellate, margin denticulate, apex obtuse or slightly acute. Column ca. 2 mm; foot ca. 6 mm; anther cap subconic, ca. 2 mm, densely bristly, front margin lacerate, apex broadly obtuse and concave.
The Taiwanese form has consistently concolorous flowers with pink sepals and petals.
Lithophytic on rocks in valleys or epiphytic on tree trunks in dense forests; 800-1900 m. E and N Guangxi (Lingchuan, Lingui), SE Hunan (Zixing), W Taiwan (Jiayi to Miaoli), SE to W Yunnan [Bhutan, NE India, Myanmar, N Thailand, Vietnam].