北美车前 bei mei che qian

Herbs, annual or winter annuals. Taproot tenuous. Leaves basal; petiole 0.5-5 cm, winged or not winged; leaf blade oblanceolate, spatulate, or obovate-lanceolate, (2-)3-18 × 0.5-4 cm, sparsely white pubescent, veins (3 or)5, base narrowly cuneate to decurrent onto petiole, margin repand, irregularly dentate, or subentire, apex acute to obtuse. Spikes narrowly cylindric, (1-)3-18 cm, base usually interrupted; peduncle 4-20 cm, hollow, densely white pubescent. Sepals as long as or slightly shorter than bract, pubescent; lower sepals obovate, keel not extending to apex; upper sepals broadly ovate, keel narrower and projected at apex. Corolla yellowish, glabrous; lobes ovate-lanceolate, 1.5-2.5 mm, erect to reflexed, apex acuminate. Stamens adnate to near apex of corolla tube, included or exserted; anthers yellowish, narrowly ovoid to broadly ellipsoid, 0.3-1.1 mm. Pyxis ovoid, 2-3 mm, circumscissile near base, with 2 seeds. Seeds light brown, ovoid to narrowly ovoid, (1-)1.4-1.8 mm, with a shallow groove on ventral face; cotyledons parallel to ventral side. Fl. Apr-May, fr. May-Jun. 2n = 12, 24.

Naturalized in grasslands, roadsides, and lake banks; near sea level to 800 m. Anhui, Chongqing, Fujian, Guangxi, Hubei, Hunan, Jiangsu, Jiangxi, Taiwan, Zhejiang [native to North America; naturalized in Central America, Europe, and Japan].

Plantago virginica was first collected in China in Nanchang Shi, Jiangxi, in 1951. In China this species usually has cleistogamous cosexual flowers. Cleistogamous female flowers and chasmogamous male flowers are rare. Cleistogamous cosexual flowers have erect corolla lobes, included anthers and stigma, and narrowly ovoid ca. 0.3 mm anthers. Cleistogamous female flowers are similar to cosexual flowers but with vestigial anthers and an exserted stigma. Chasmogamous male flowers have patent to reflexed corolla lobes, exserted stamens, broadly ellipsoid 1-1.1 mm anthers, and often a vestigial ovary.

In North America Plantago virginica is typically cleistogamous and cosexual; however, flowers, inflorescences, or entire plants are frequently chasmogamous and functionally male or cleistogamous with exserted stigmas and functionally female.