蓝花车叶草 lan hua che ye cao

Asperula arvensis Linnaeus subsp. orientalis (Boissier & Hohenacker) Thiébaud; A. azurea Jaubert & Spach.

Herbs, annual, from fibrous roots. Stems few or solitary, to 30(-40) cm tall, 4-angled, erect, often regularly divaricately branched, glabrous to scaberulous or hispidulous. Leaves and leaflike stipules at middle stem regions in whorls of 4-8, subsessile; blade drying papery, lanceolate, linear-lanceolate, or spatulate, (7-)12-25(-30) × (1.5-)2-5(-10) mm, glabrous to sparsely hispidulous on lamina and densely scaberulous to antrorsely aculeolate on veins and margins, base acute, apex obtuse to rounded; secondary veins not evident. Inflorescences terminal, capitate to subcapitate; peduncles 1.5-4 cm; involucral bracts leaflike, 1-12 mm, white ciliate at margins. Flowers sessile. Corolla pale to clear purplish blue, salverform, outside densely papillose; tube 8-10 mm, dilated in throat around anthers; lobes 4, elliptic to ovate, 2-3 mm, obtuse. Ovary ovoid, ca. 1 mm, glabrescent. Mericarps 1-1.8 mm, glabrous. Fl. Jun-Jul, fr. Aug-Sep.

Cultivated ornamental in Anhui, Jiangsu (Nanjing), and Shaanxi (Xi’an) [native to SW Asia (Georgia, Iraq, Lebanon, Syria, Turkey)].

Asperula orientalis is a butterfly-pollinated SW Asiatic member of A. sect. Asperula. Pobedimova et al. (Fl. URSS 23: 283. 1958) erroneously gave the name A. azurea priority over A. orientalis. The other closely related taxa of A. sect. Asperula are the smaller-flowered and widespread A. arvensis Linnaeus (the conserved type of the genus) and A. setosa Jaubert & Spach. The latter has very small flowers, is obviously autogamous, and grows at higher elevations (1200-3200 m) from SW Asia to the Tian Shan and Pamir-Alai. It could be found in the mountains of W China.