串花马蓝 chuan hua ma lan

Pteracanthus botryanthus (D. Fang & H. S. Lo) C. Y. Wu & C. C. Hu; Strobilanthes botryantha D. Fang & H. S. Lo; S. myriostachya D. Fang & H. S. Lo.

Subshrubs 1.5-3.5 m tall, isophyllous, drying green. Stems 4-angled, sulcate, glabrous. Petiole 0.5-2 cm, sulcate; leaf blade narrowly elliptic, narrowly ovate, or rarely ovate-elliptic, (2-)4-17 × 1.5-4.5 cm, glabrous, densely covered with linear cystoliths, secondary veins 4-6 on each side of midvein, base cuneate and decurrent onto petiole, margin subentire to irregularly crenate, apex acuminate. Inflorescences axillary, spikes, 2-6(-12) cm, sometimes branched, (2-)8-14-flowered; peduncle 0.5-1.5 cm; bracts elliptic, 4-6 × 3-4 mm, persistent, abaxially with prominent cystoliths and frequently a single black squamate gland, margin ciliolate, apex obtuse to acute; bracteoles ovate-lanceolate, ca. 5 × 1 mm, glabrous except for ciliolate margin, densely covered with cystoliths, apex acute. Flowers in opposite pairs, ca. 0.5 mm apart on rachis. Calyx 8-10 mm, subequally 5-lobed to base; lobes linear-lanceolate, 5-6 × ca. 1 mm, basally overlapping, glabrous, apex obtuse. Corolla purple, 3-4.5 cm, slightly curved, outside glabrous, inside glabrous except for trichomes retaining style; tube basally cylindric and narrow for ca. 1 cm then gradually widened to ca. 1.8 cm at mouth; lobes broadly ovate, ca. 6 × 7 mm, apex rounded. Stamens 4, included; filaments pilose, shorter pair ca. 2 mm, longer pair ca. 5 mm; anther thecae oblong, ca. 2 × 1 mm; pollen type 3. Ovary glabrous; style ca. 2.8 cm, hirsute; stigma glabrous. Capsule oblong, ca. 1.7 cm, glabrous, 4-seeded. Seeds ovate in outline, ca. 1 cm, pilose; areola small, glabrous. Fl. Sep-Nov, fr. Dec.

Ravines or streamsides on limestone hills; 800-1200 m. Guangxi, Hainan, Yunnan [Vietnam].