飞来蓝 fei lai lan

Leptosiphonium venustum (Hance) E. Hossain; Ruellia seclusa S. Moore.

Herbs to 70 cm tall, unbranched or rarely branched. Petiole 3-8 mm; leaf blade oblong-lanceolate, lanceolate, or oblanceolate, 4-14 × 1-3.5 cm, both surfaces glabrous, secondary veins 5-8 on each side of midvein, base cuneate to attenuate and decurrent onto petiole, margin slightly undulate to crenate, apex acute to acuminate. Flowers in axils of leaves or leaflike bracts, solitary or in dichasial clusters, sessile; bracteoles subleaflike, lanceolate to elliptic, 7-30 × 1.5-6.5 mm, abaxially glabrous. Calyx 7-8 mm; lobes lanceolate, outside sparsely pubescent with non-glandular trichomes, adaxially gland-tipped puberulent. Corolla purplish white, 4-5.5 cm; tube basally cylindric and ca. 2 mm wide for 2.2-3.5 cm; lobes 7-17 × 4-6 mm, subequal, apically undulate. Stamens with longer pair ca. 7 mm and shorter pair ca. 4 mm; filaments glabrous; anther thecae ca. 2 mm. Ovary glabrous; style sparsely villous. Capsule ca. 1.3 cm. Fl. Aug-Sep.

● Forests, along streams; 100-800 m. Anhui, Fujian, Guangdong, Guangxi, Hubei, Hunan, Jiangxi.

Ruellia venusta was treated under Leptosiphonium F. Mueller by C. C. Hu (FRPS 70: 56-58. 2002). Leptosiphonium is often treated as a section of Ruellia. The generic distinctions between Leptosiphonium and most Ruellia are based on floral form and color (white or yellowish corollas that are hypocrateriform in Leptosiphonium) and likely reflect different pollinators. It is doubtful that the genera are distinct, but the Chinese plants (with their purplish and funnelform corollas) more closely resemble those of Ruellia than Leptosiphonium.