Oenothera villosa Thunb.

Herbs erect, biennial, with taproot and basal rosette. Stems 50-200 cm tall, simple or sparsely branched, exclusively densely strigillose, or sometimes with few subappressed or spreading pustulate-based hairs or few glandular hairs on floral tube. Leaves gray-green, with prominent pale or red veins, especially abaxially, sessile; rosette blade 10-30 × 1.2-4(-5) cm; cauline blade narrowly lanceolate or oblanceolate to elliptic, 5-20 × 1-2.5(-4) cm, base obtuse to attenuate, margin conspicuously dentate, apex acute. Inflorescence a dense unbranched spike. Flowers open near sunset; floral tube 2.3-4.4 cm. Sepals 9-18 mm, with free tips 0.5-3 mm, apical, erect. Petals yellow to pale yellow, 7-20 mm. Anthers 4-10 mm; pollen ca. 50% fertile. Ovary densely strigillose; stigma surrounded by anthers. Capsules grayish green, lanceoloid, 2-4.3 cm, sessile. Seeds in two rows per locule, brown to nearly black, 1-2 mm, angled, irregularly pitted. Fl. Jul-Sep, fr. Aug-Oct. 2n = 14, permanent translocation heterozygote; self-compatible, autogamous, often cleistogamous.

Heilongjiang, Jilin, Liaoning [native to EC North America; naturalized in Japan, Russia (Far East), and widely in S Africa, Asia, Europe, and S South America].

Open disturbed sites, seasonally moist but often somewhat dryer sites than O. biennis and O. parviflora; near sea level to 1200 m.

Oenothera villosa là một loài thực vật có hoa trong họ Anh thảo chiều. Loài này được Thunb. mô tả khoa học đầu tiên năm 1794.

长毛月见草（学名：Oenothera villosa）为柳叶菜科月见草属下的一个种。