3. Rumex acetosa Linnaeus, Sp. Pl. 1: 337. 1753.
酸模 suan mo
Acetosa pratensis Miller.
Herbs perennial, dioecious, with a short and relatively thin horizontal or slightly oblique rootstock, usually not reaching deep into substrate and with rather crowded secondary roots. Stems erect, 40-100 cm tall, grooved, glabrous, usually simple. Basal leaves ovate-lanceolate to lanceolate, base sagittate, 3-12 × 2-4 cm, margin entire, apex acute, basal lobes acute at apices; cauline leaves small; petiole short or nearly absent; ocrea fugacious, white, membranous. Inflorescence terminal, paniculate, lax; branches reddish green, slender, simple or with a few secondary branches. Flowers unisexual. Pedicel slender, articulate at middle. Male flowers: outer tepals erect, small; inner tepals elliptic, ca. 3 mm. Female flowers: outer tepals elliptic, reflexed in fruit; inner tepals enlarged in fruit; valves nearly orbicular (to broadly ovate), 3.5-4 mm in diam., with small recurved tubercles at base of valves, net veined, base cordate, margin entire, apex obtuse. Achenes blackish brown, shiny, ellipsoid, trigonous, ca. 2 mm. Fl. May-Jul, fr. Jun-Aug. 2n = 14*, 15*, 22*.
Mountain slopes, forest margins, moist valleys; 400-4100 m. ?Anhui, ?Fujian, ?Guangxi, ?Guizhou, Heilongjiang, ?Henan, Hubei, ?Hunan, Jiangsu, Jilin, Liaoning, Nei Mongol, Qinghai, ?Shaanxi, ?Shandong, ?Shanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, ?Zhejiang [Japan, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Russia; Europe, North America].