变色马蓝 bian se ma lan

Pteracanthus versicolor (Diels) H. W. Li.

Herbs to 50(-100) cm tall, with several annual stems arising from a perennial base, isophyllous. Stems sparsely to densely pubescent, glabrescent. Petiole (0-)1-3 cm, pubescent; leaf blade obovate to suborbicular, 2.5-6 × 1-3.5 cm, both surfaces thinly pilose especially on veins, densely covered with cystoliths, secondary veins 4-6 on each side of midvein, base broadly cuneate and decurrent onto petiole, margin coarsely serrate, apex acute. Inflorescences terminal or axillary, spikes, 4-15 cm, simple or sparingly branched; bracts leaflike, 1.2-3.5 × 0.3-1 cm, persistent, apically diminishing in size, thinly pilose; basal bracts petiolate, suborbicular to oblong-elliptic, margin dentate; apical bracts sessile, narrowly oblong-elliptic, margin entire; bracteoles linear-oblanceolate, 4-8 × 1-2 mm, pilose. Flower pairs 1-1.5 cm apart on rachis even apically. Calyx ca. 1.5 cm, 5-lobed almost to base; lobes linear, 10-11 × ca. 1 mm, subequal, pilose with large-celled trichomes, apex obtuse. Corolla white or blue, 3.5-4 cm, outside pilose, inside glabrous except for trichomes retaining style; tube basally cylindric and ca. 2.5 mm wide for 1-1.5 cm then abruptly bent to ca. 90° above middle and finally widened to ca. 1.5 cm at mouth; lobes ovate, ca. 6 × 5 mm, apex rounded. Stamens 4, included; filaments pilose, shorter pair ca. 5 mm, longer pair ca. 7 mm; anther thecae oblong, 2-2.5 × ca. 0.8 mm; pollen type 6. Ovary comose; style ca. 2.8 cm, pilose. Capsule ca. 1.4 cm, gland-tipped pubescent, 4-seeded. Seeds ovate in outline, ca. 3 × 3 mm, appressed pubescent. Fl. May-Aug.

● Grasslands at forest margins; 2800-3300 m. Sichuan, S Xizang, Yunnan.