4. Oenothera oakesiana (A. Gray) J. W. Robbins ex S. Watson & Coulter, Manual, ed. 6. 190. 1890.
曲序月见草 qu xu yue jian cao
Oenothera biennis Linnaeus var. oakesiana A. Gray, Manual, ed. 5, 190. 1867.
Herbs erect to procumbent, biennial, with taproot and basal rosette. Stems 10-60 cm tall, simple or branched, densely strigillose throughout, mixed with long erect hairs and/or suberect red pustulate-based hairs, and often glandular hairs on inflorescence. Leaves grayish green, with inconspicuous veins, densely strigillose, sessile or shortly petiolate; rosette blade 8-30 × 0.5-3 cm; cauline blade very narrowly oblanceolate to narrowly elliptic, 3.5-20 × 0.5-2.7 cm, base narrowly cuneate to attenuate, margin remotely dentate to subentire, apex acute to narrowly so. Inflorescence a dense unbranched spike, nodding or sigmoid. Flowers open near sunset; floral tube 1.5-4 cm. Sepals 9-17 mm, with free tips 2.5-4 mm, subapical, erect or spreading. Petals yellow, fading to reddish orange, 7-20 mm. Anthers 3-7 mm; pollen ca. 50% fertile. Ovary densely strigillose, with spreading and glandular hairs mixed; stigma surrounded by anthers. Capsules green, drying rusty brown, narrowly lanceoloid, 1.5-4 cm, sessile. Seeds in (1 or)2 rows per locule, dark brown to nearly black, 1.1-1.2 mm, irregularly pitted. Fl. Jul-Sep(-Oct), fr. Aug-Oct. 2n = 14, permanent translocation heterozygote; self-compatible, usually autogamous.
Sandy coastal meadows and dunes or on gravelly sites along rivers, also in disturbed sites such as roadsides; near sea level to 500 m. Fujian [native to E North America, naturalized in Europe].
This species is known only from Fujian Province in China, and has not been reported as naturalized elsewhere in Asia.