2. Plagiopetalum tenuicaule (C. Chen) C. Hansen, Bull. Mus. Natl. Hist. Nat., B, Adansonia. 10: 134. 1988.
四棱偏瓣花 si leng pian ban hua
Phyllagathis tenuicaulis C. Chen, Bull. Bot. Res., Harbin 4(3): 42. 1984.
Herbs 12-22 cm tall. Stems slender, 4-sided, narrowly winged on angles, wings with sparse glandular trichomes, nodes hispid. Petiole ca. 8 mm to subsessile, with glandular trichomes; leaf blade ovate to broadly ovate, 0.9-1.9 × 0.6-1.4 cm, papery, abaxially sparsely strigose on veins, adaxially sparsely strigose, secondary veins 1(or 2) on each side of midvein, base cuneate to subcordate, margin denticulate, apex acute. Inflorescences terminal, cymes, 1.5-2.2 cm, 1-3-flowered; peduncle ca. 1 cm, with sparse glandular trichomes. Pedicel ca. 1 mm, bracteolate at base. Hypanthium bell- or funnel-shaped, 4-sided, ca. 3.5 mm, with glandular trichomes. Calyx lobes broadly triangular, apex acute with a ca. 0.5 mm aristate tip. Petals purplish red, subround, ca. 6 × 5 mm, minutely oblique, base shortly unguiculate, apex acute with 1 glandular trichome at tip. Stamens equal, ca. 5.5 mm; anthers lanceolate, ca. 2.5 mm; connective minutely inflated. Ovary broadly ovate, apex 4-dentate. Fl. Aug.
● Mountain slopes, grassy areas; ca. 1700 m. Guangxi.