四子马蓝 si zi ma lan

Ruellia tetrasperma Champion ex Bentham, Hooker’s J. Bot. Kew Gard. Misc. 5: 132. 1853; Acanthopale radicans (T. Anderson ex Bentham) C. B. Clarke ex Benoist; A. tetrasperma (Champion ex Bentham) Handel-Mazzetti; Championella tetrasperma (Champion ex Bentham) Bremekamp; Strobilanthes radicans T. Anderson ex Bentham.

Herbs 30-50 cm tall, isophyllous. Stems often procumbent and rooting at base, 4-angled, sulcate, retrorsely pubescent along sulci, glabrescent, basally slightly woody. Petiole 0.5-2.5 cm, sulcate, glabrous; leaf blade ovate, elliptic, or oblong, 1.5-11 × 1-4.5 cm, glabrous, adaxially darker and densely covered with cystoliths, secondary veins ca. 5 on each side of midvein, base attenuate or decurrent onto petiole, margin serrate to dentate, apex acuminate to acute. Inflorescences terminal or (sometimes) axillary, short often headlike spikes, few flowered, often reduced to a single flower pair; bracts leaflike, obovate to spatulate, 1-1.5 × 0.4-0.5 cm, sparsely pilose, pinnately veined; bracteoles linear, 5-6 × ca. 1 mm, abaxially glabrous or sparsely pilose and densely covered with cystoliths. Calyx 5-lobed almost to base; lobes linear, 5-7 × ca. 1 mm, accrescent to ca. 8 mm in fruit, glabrous except for large-celled trichomes on margin, densely covered with cystoliths. Corolla purple to purplish blue, funnel-shaped, 1.5-2 cm, straight, outside pubescent, inside villous; tube basally cylindric and ca. 2 mm wide for ca. 5 mm then gradually widened to ca. 1.5 cm at mouth; lobes oblong, ca. 4 × 5 mm, apex obtuse. Stamens 4, included; shorter filament pair ca. 2 mm, glabrous; longer filament pair ca. 5 mm, sparsely pubescent; anther thecae oblong, ca. 2 mm; pollen type 10. Ovary ovoid, ca. 3 mm, hispid at tip, with 4 ovules per locule; style ca. 1.5 cm, hirsute; stigma 2-lobed, lobes unequal. Capsule oblong, 7-10 mm, apically pubescent, 4-seeded. Seeds ovate in outline, ca. 2 × 2 mm, pubescent. Fl. Jul-Dec.

Forests, shaded grasslands, rocks by streams, roadsides; 100-1000 m. Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Sichuan [Vietnam].