Herbs, erect, with clear latex in all parts. Leaves opposite, sessile, linear to linear-lanceolate, coriaceous, base attenuate, margins entire, slightly revolute, apex acute to acuminate. Inflorescence 1–flowered cyme, axillary or extra-axillary. Calyx deeply 5-parted, lobes yellowish green or green, narrowly lanceolate, glabrous, apex sharply acute, pink. Corolla tubular-urceolate, straight; corolla tube purplish or reddish brown, glabrous, slightly inflated at base; lobes linear, long caudate, outside brown or purplish brown, inside green or greenish brown, margins slightly reflexed, auriculate; upper parts overlapping and dextrorsely tightly twisted. Corona double. Pollinium broadly ovoid, yellow. Ovaries 2, ovoid, glabrous. Fruits follicles, usually 2, linear-lanceolate in outline, green when young, turning reddish brown with age. Seeds ovate-oblong, with a single coma of hairs, silky white.

Perennial, pendant, with watery latex in all parts. Leaves opposite, broadly ovate, succulently leathery, cordate at base, with entire margins, acuminate at apex, hirsute. Inflorescence extra-axillary, 1- or 2-flowered. Calyx deeply 5-parted; lobes green or greenish or reddish brown, lanceolate, sharply acute at apex, glabrous. Corolla upright, curved; corolla tube tubular-urceolate, greenish white or pinkish white, glabrous, slightly inflated at base, then narrowing into a tube; lobes ovate, glabrous, obtuse at apex, apically connate and forming a cage-like structure, greenish white, with reflexed margins. Corona double, sessile. Pollinium broadly ovoid, yellow. Fruits follicles, usually 2, linear, green turning reddish brown with age. Seeds brown, oblong, with a single coma of silky white hairs.

Herbs, erect, with clear latex in all parts. Leaves opposite, decussate, sessile, linear to linear-lanceolate, coriaceous, base attenuate, margin entire, slightly revolute, apex acute to acuminate. Flower solitary, extra-axillary, sessile. Sepals yellowish-green or green, narrowly lanceolate, glabrous, apex sharply acute. Corolla tubular-urceolate, upright, straight to slightly curved; corolla tube yellow to yellowish-white with 5 purple lines alternate the sepal, base slightly inflated to a narrow ovoid shape; corolla lobes yellow, speckled yellowish-brown at apex, broadly obovate, apex shortly acuminate, connate at tips. Gynostegial corona double, interstaminal lobes joined to form a shallow cup, purple, shortly pilose inside; staminal corona lobes terete, yellowish-purple. Pollinium broadly ovoid, yellow. Follicles usually 2, linear-lanceolate in outline. Seeds ovate-oblong, coma silky white.

Terrestrial, sympodial herb. Pseudobulbs green, slenderly obconical to terete. Foliage leaves 4–7; lamina falcate to narrowly lanceolate or often falcately lanceolate with slightly asymmetrical base, acuminate, glabrous, margins undulate. Inflorescence terminal on the young pseudobulb, racemose, erect, 7–21 cm long, laxly 15- to 35-flowered, glabrous; peduncle dull purple. Flowers non-resupinate, light green to yellowish green, sometimes more or less tinged with purple, 1.5–4 mm in diam. Sepals free, glabrous, with recurved margins. Petals free, patent, linear to oblong, rounded to obliquely retuse, margins revolute. Labellum perpendicular to column, longer thanwide, elliptic to elliptic-oblong, constricted at the middle and with strongly sagittate auriculate base, distally bilobed with rounded, usually incurved lobes. Pollinia 4 in 2 pairs, (sub)equal in size, obliquely clavate, hard. Ovary green tinged with purple, fusiform-cylindrical, with 6 longitudinal ridges, glabrous.

Plant epiphytic, tufted. Pseudobulbs erect, fusiform or cylindric. Foliage leaves 2–3, distichous, spreading, slightly recurved, linear-oblong, elliptic or oblong, 2–3 × 3–5 mm, apex unequally and shortly 2-lobed, each lobe acute, base expanded into sheaths, chartaceous, glabrous on both sides. Inflorescences raceme, 1–2-inflorescenced, axillary and terminal, erect, 1.3–2.5 cm long, lax, 3–5-flowered. Flowers resupinate, waxy and polished, scented, long-lasting, 6–8 mm in diam. Sepals pale green with dull green at base, spreading, often recurved distally, margin entire, abaxial surface distinctly keeled. Petals green, with 3 longitudinal light reddish-purple veins, spreading, linear-oblanceolate, apex acute, base truncate, margin entire. Labellum light green with reddish-purple dots, recurved at apex, 3-lobed, attenuate at base. Column glossy green with slight purple tinge, short. Pollinia 4, bright yellow, in 2 pairs, each pollinium narrowly elliptic. Ovary narrowly clavate, curved, glabrous, somewhat waxy, 6-grooved.

Epiphytic herbs. Pseudobulbs cylindric or narrowly fusiform. Leaves 2–4, distichous, spreading, slightly recurved, ovate, lanceolate, narrowly lanceolate or oblong-lanceolate, 4.5–8.0 × 0.5–1.3 cm, apex unequally and shortly bilobed, each lobe acute, base expanded into sheaths, glabrous on both surfaces. Inflorescences with 1–4 subterminal and axillary racemes, 2.5–5.5 cm long, not exceeding leaves, lax, 2–3-flowered. Flowers resupinate, waxy, strongly fragrant, 1.4–1.6 cm in diameter. Sepals greenish yellow with 3 longitudinal purple veins, spreading, often recurved distally, margin entire, abaxial surface distinctly keeled. Petals pale green or greenish yellow, with 3 longitudinal purple veins, spreading, oblanceolate, apex acuminate, base truncate, margin entire, sometime slightly undulate in upper half. Labellum bright greenish yellow or dull green, recurved at apex, ovate or suborbicular and distinctly trilobed. Column green, margin entire. Pollinia 4, in 2 pairs, yellow, each pollinium narrowly elliptic. Ovary narrowly clavate, curved, glabrous, waxy, 6-grooved. Capsule green, ellipsoidal, with 3 obtuse keels, apex with scarious, persistent sepals and petals.