纤序马蓝 xian xu ma lan

Subshrubs to 1 m tall, anisophyllous. Stems 4-angled, sulcate, glabrous. Petiole 0.1-3.4 cm, usually very short on smaller leaves, often sulcate, glabrous; leaf blade ovate to ovate-elliptic, 1-13 × 0.5-8 cm, smaller of pair 1/4-1/3 size of larger one, glabrous except for multicellular trichomes in teeth sinuses, adaxially cystoliths prominent, secondary veins 5-7 on each side of midvein and abaxially prominent, base oblique and broadly cuneate, rounded, or slightly cordate, margin slightly serrate to subentire, apex acuminate. Inflorescences terminal, panicles, to 10 cm; peduncle to 3 cm, glabrous; rachis slender, glabrous, repeatedly 3-forked and bent to ca. 90º; bracts subulate, ca. 1 mm, caducous; bracteoles similar to bracts. Flowers 1 per node. Calyx 4-6 mm, accrescent to ca. 8 mm in fruit, glabrous, 5-lobed almost to base; lobes oblong to oblong-lanceolate with one slightly longer than others, margin pale, apex emarginate. Corolla white, 3.2-4 cm, straight, outside glabrous, inside glabrous except for trichomes retaining style; tube basally cylindric and ca. 1.5 mm wide for 6-10 mm then slightly ventricose and gradually widened to ca. 1.5 cm at mouth; lobes ovate, ca. 5 × 5 mm, apex acute. Stamens 4, included; filaments glabrous, shorter pair ca. 0.5 mm, longer pair 4-5 mm; anther thecae spherical, ca. 1 mm in diam., partially recurved. Ovary glabrous; style 2.5-3.2 mm, glabrous. Capsule oblong, ca. 1.5 cm, glabrous, 4-seeded, apex acuminate. Seeds ovate in outline, ca. 2 × 1.5 mm, puberulent. Fl. Oct.

Forests; ca. 900 m. Yunnan (Cangyuan) [Thailand].