瘦叉柱花 shou cha zhu hua

Herbs to 1 m tall, usually ascending from a decumbent base and rooting at nodes on lower portion. Stems striate and lenticellate, glabrous. Petiole 3-6 cm; leaf blade elliptic, oblong, or lanceolate, 13-17 × 4.5-7 cm, both surfaces glabrous, secondary veins 8-11 on each side of midvein, base cuneate and slightly decurrent onto petiole, margin entire or undulate, apex acuminate to acute. Racemes terminal or axillary from apical leaves, to 15 cm, unbranched or with 2 branches at base; rachis gland-tipped pubescent; bracts linear, 4-4.5 × ca. 0.8 mm, pinnately veined, apex acuminate; bracteoles linear, ca. 2 × 0.5 mm. Pedicel 2-3.5 mm. Calyx ca. 5 mm, outside pubescent with gland-tipped trichomes. Corolla white, funnel-shaped, ca. 7 mm; lobes suborbicular, ca. 1.5 × 1.3 mm, subequal, apex rounded. Stamens with longer pair ca. 3 mm and shorter pair ca. 2 mm; filaments glabrous; anther thecae ca. 1 mm. Ovary ellipsoid, ca. 2 × 1 mm, glabrous; ovules 12 in 2 rows per locule; style ca. 3 cm, glabrous; stigma 2-lobed. Capsule cylindric, 5-7 mm. Fl. Dec-May.

Forests along streams. Hainan, Yunnan [Vietnam].