落花生 luo hua sheng

Lathyrus esquirolii H. Léveillé.

Herbs, annual, erect to decumbent. Stems erect or procum­bent, (6-)30-80 cm tall, yellowish pubescent, glabrescent. Stipules 2-4 cm, pilose. Leaves usually 4-foliolate; petiole 3.7-10 cm, covered with long flexuous trichomes, basally adnate to stipule; petiolules 1-10 mm, velutinous; leaflet blades ovate-oblong to obovate, 1.1-5.9 × 0.5-3.4 cm, papery, both surfaces with long trichomes, veins ca. 10 on each side of midvein, base almost rounded, margin ciliate, apex obtuse or emarginate and mucronate. Bracts lanceolate, apex acuminate. Flowers 8-10 mm, sessile; bracteoles lanceolate, ca. 5 mm, velutinous. Calyx tube 4-6 mm, thin. Corolla yellow to golden yellow; standard spreading, apex emarginate; wings distinct, oblong to obliquely ovate, slender; keels distinct, long ovate, shorter than wings, inflexed, apex acuminate to beaked. Ovary oblong; style longer than calyx; stigma terminal, small, sparsely pubescent. Legume geocarpic, oblong, inflated, 2-5 × 1-1.3 cm, thick-walled, retic­ulate veined, with 1-4(-6) seeds. Seeds light brown, oblong, 5-10 mm in diam. Fl. May-Aug, fr. Jul-Sep. 4n = 40.

Grown in sandy warm areas. Cultivated in Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Ningxia, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Yunnan, and Zhejiang [native to tropical South America].

Peanuts are grown over much of China except for Heilongjiang, Qinghai-Xizang Plateau, and Xinjiang. In addition to being used for food, they are used as a source of oil, soap, cosmetics, green fertilizer, fodder, and paper.