Trigonotis formosana Hayata

Herbs perennial, runners usually floriferous. Stems not branched, 10-20 cm tall, usually strigose. Basal leaves long elliptic to lanceolate, 2-5 cm, base narrowly cuneate and decurrent to petiole, apex rounded, mucronate; stem leaves short petiolate, shorter, wider than basal leaves. Inflorescences (1 or) 2 or 3(-5), terminating branches, 5-15 cm, many flowered, ebracteate. Pedicel erect, 1-3 mm. Flowers crowded. Calyx lobes ovate-triangular, 0.5-1.5 mm, apex ± acute. Corolla tube ca. 1 mm; limb 2-3 mm wide; lobes broadly elliptic, 1-1.5 mm. Stamens inserted at middle of corolla; anthers ca. 0.3 mm. Mature nutlets black, inverted subulate, trigonous-tetrahedral, ca. 1 mm, shiny, adaxial 3 surfaces subequal in size; abaxial surfaces triangular, flat, glabrous, sometimes with 1-3 bristles near inside corner, sessile. 2n = 48*.

* Mountains. Taiwan.