田紫草 tian zi cao

Buglossoides arvensis (Linnaeus) I. M. Johnston; Rhytispermum arvense (Linnaeus) Link.

Herbs annual. Roots with purple dye. Stems usually single, branched from base or only above, 15-30 cm tall, short strigose. Leaf blade oblanceolate to linear, 2-4 cm × 3-7 mm, short strigose, apex acute. Cymes terminal, to 10 cm; bracts same shape as leaves but smaller. Flowers sparse, short pedicellate. Calyx lobes usually erect, linear, 4-5.5 mm, to 1.1 cm in fruit, short strigose on both sides, base becoming slightly hardened. Corolla white, sometimes blue or light blue, salverform; tube ca. 4 mm, sparsely pubescent outside; throat with 5 bands of hair extending to tube; limb ca. 1/2 as long as tube; lobes somewhat unequal, erect to slightly spreading, ovate or oblong, ca. 1.5 mm. Stamens attached below middle of tube; anthers oblong, ca. 1 mm. Style 1.5-2 mm; stigma capitate. Nutlets gray-brown, triangular-ovoid, ca. 3 mm, finely tuberculate. Fl. and fr. Apr-Aug. 2n = 14, 28, 36, 42.

Hills, pastures, mountain slopes, margins of cultivated ground. Anhui, Gansu, Hebei, Heilongjiang, Hubei, Jiangsu, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, Xinjiang, Zhejiang [Afghanistan, N India, Japan, Kashmir, Kazakhstan, Korea, Kyrgyzstan, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; SW Asia, Europe]

A highly variable species with several infraspecific taxa recognized in Europe.