Description from Flora of China
Ceratostema angulatum Griffith, Not. Pl. Asiat. 4: 302. 1854.
Shrubs 0.8–1.3 m tall, glabrous. Twigs angled, 4–5 mm in diam., becoming lenticellate. Leaves scattered; petiole 0.5–1 cm; leaf blade lanceolate or elliptic-lanceolate, 12–14 × 3.5–4 cm, thinly papery, secondary veins 8 or 9 pairs, raised abaxially, base cuneate, margin sparsely serrulate, apex acuminate. Inflorescences corymbose to subumbellate, 2.5–4 cm, 5–15-flowered; rachis 0.4–1.5 cm. Pedicel 0.9–2.2 cm, slender, expanded at apex. Calyx tube obpyramidal, 1.5–1.7 mm, slightly 5-angled; limb 1.6–2.5 mm, divided ca. 4/5; lobes triangular, 1.2–2.3 mm. Corolla red to reddish yellow, with deep colored zig-zag bands, 1.5–2.7 cm, rather thinly fleshy; lobes green, triangular, 3.5–6 mm. Filaments 1–2 mm, with sparse hairs; anthers ca. 2.6 cm, thecae rounded to acute, somewhat downward-pointing at base, papillate, tubules ca. 4 × as long as thecae, spurs absent. Fl. Feb–Mar, fr. May.
Forests, epiphytic on trees; (700–)1200–1500 m. SE Xizang, NW Yunnan (Dulongjiang) [NE India (Assam), Myanmar].