密序马蓝 mi xu ma lan

Pteracanthus congestus (Terao) C. Y. Wu & C. C. Hu.

Subshrubs 0.6-1.8 m tall, anisophyllous. Stems subterete, whitish to brownish yellow pubescent with large-celled trichomes. Petiole 1-7 mm, densely hirsute; leaf blade ovate-lanceolate, 2-9 × 0.8-3.5 cm, smaller of pair ca. 2/3 size of larger one, both surfaces brownish to yellow hirsute, secondary veins 4-7 on each side of midvein and inconspicuous, base attenuate, oblique, and shortly decurrent onto petiole, margin crenate and ciliate, apex acuminate and often falcate. Inflorescences axillary or terminal, spicate with 1-4 small capitula borne singly along rachis; capitula 2-8-flowered, to 4 cm apart; rachis 3-7 cm, often basally with a pair of sterile leaflike bracts so leaves sometimes appearing verticillate, densely white or yellow pilose; bracts linear-oblanceolate, 3-8 × 0.8-1.5 mm, persistent, pilose, apex obtuse; bracteoles ca. 6 × 1 mm, linear, white pilose. Calyx 5-lobed almost to base; lobes ovate to lanceolate, pilose on both surfaces except basally inside, abruptly narrowed at middle with an obtuse often apically recurved cauda 11-14 × 1.5-5 mm; one lobe ca. 2 mm longer than others. Corolla pale whitish purple, ca. 2.5 cm, curved, outside pubescent; tube basally narrow and cylindric for ca. 6 mm then abruptly inflated and widened to ca. 1 cm at mouth; lobes oblong, ca. 4 × 3.5 mm. Stamens 4, included; shorter filament pair ca. 3 mm, glabrous; longer filament pair 5-6 mm, base pilose; anther thecae oblong, ca. 2 × 0.5 mm; pollen type 3. Ovary glabrous; style ca. 1.8 cm, pilose and gland-tipped pubescent. Capsule oblong, ca. 10 × 3 mm, glabrous, 4-seeded; seeds ovate in outline, ca. 3 × 2.5 mm, pubescent. Fl. Jul-Aug, fr. Dec.

Thickets, tropical forests; 1600-1800 m. Yunnan [Myanmar, ?Nepal].

Strobilanthes congesta is a very distinct species because of the form of its inflorescence and unique calyx.