2. Exacum teres Wallich in Roxburgh, Fl. Ind. 1: 414. 1820.
云南藻百年 yun nan zao bai nian
Plants (15-)30-100 cm tall. Stems erect or ascending, little branched, terete. Leaves sessile, narrowly ovate to lanceolate, 4-10 × 0.8-2.5(-3) cm, base cuneate, apex mostly acute but sometimes blunt on basal leaves; veins 3, prominent. Cymes mostly 3flowered in a narrow racemelike inflorescence; peduncle to 1.5 cm, flattened, to 3 cm in fruit; bracts mostly linear, sometimes leaflike. Pedicel 0.5-2(-3) mm. Calyx 7-10 mm; lobes ovate, apex acuminate, midvein raised into a narrow wing. Corolla bright blue fading to purple and drying to purplish pink, 2.5-3 cm in diam.; tube ca. 0.7 cm; lobes 1.2-1.6 cm. × 6-7 mm, apex short acuminate. Filaments 2-3 mm; anthers (6.5-)8-10 mm. Style ca. 1.5 cm. Capsules ellipsoid, 7-12 × 5-8 mm. Seeds polygonal to brick-shaped, with a prominent, pale brown, spongy, loose outer coat opening to reveal dark brown, ellipsoid seed ca. 0.8 mm.
Disturbed sites, often along roadsides, on scree slopes or river beds; 0-1500 m. Yunnan (Taying Jiang valley) [Bangladesh, Bhutan, India, Myanmar, Nepal, Sikkim]