52. Strobilanthes rubescens T. Anderson, J. Linn. Soc., Bot. 9: 479. 1867.
红色马蓝 hong se ma lan
Pteracanthus rubescens (T. Anderson) Bremekamp.
Subshrubs 0.5-2 m tall, isophyllous. Stems somewhat sulcate, pilose with large-celled trichomes, eventually glabrescent, basally woody. Petiole to 2 mm but apically leaves becoming sessile, pilose; leaf blade ovate to suborbicular, 4-10 × 2-5 cm, smaller of pair ca. 2/3 size of larger one, abaxially paler and glabrous except for a few trichomes on veins and densely covered with prominent cystoliths, adaxially green with inconspicuous cystoliths and subglabrous except for a few scattered hispid trichomes and a strigose or scurfy midvein, base rounded, cordate, or cuneate and decurrent onto petiole, margin crenulate-dentate, apex acute to shortly acuminate and commonly falcate. Inflorescences axillary, spikes, 2-5 cm, secund, sometimes reduced to solitary flowers in leaf axils; rachis straight or obscurely zigzag, pilose; sterile bracts leaflike, sessile, ovate, 1-4 × 0.7-2.2 cm, variable in development, glabrous, densely covered with cystoliths, apex acuminate; floral bracts ovate, 2-3 × 1-1.5 mm, persistent, glabrous, apex acuminate; bracteoles oblong-lanceolate, 1.5-3 × 0.5-1 mm, caducous, glabrous. Flowers to 2 cm apart basally on rachis but internodes shorter apically. Calyx 0.9-1.6 cm, subequally 5-lobed to ca. 1 mm from base; lobes almost colorless, linear, 1-2 mm wide, glabrous, covered with cystoliths, apex acute. Corolla white, 2-2.5 cm, straight, outside glabrous, inside glabrous except for trichomes retaining style; tube basally cylindric and narrow for ca. 5 mm then gradually widened to ca. 1.2 cm at mouth; lobes ovate, 4-6 mm, apex rounded. Stamens 4, included; filaments glabrous, shorter pair ca. 2 mm, longer pair ca. 6 mm; anther thecae spherical, ca. 1 mm in diam., glabrous; pollen type 3, requires confirmation. Ovary glabrous; style ca. 2 cm, glabrous. Capsule 1-1.2 cm, glabrous except hairy at tip, 4-seeded. Fl. Oct-May.
Limestone hills; ca. 1900 m. Yunnan [Bhutan, India].