天山酸模 tian shan suan mo

Herbs perennial. Stems erect, 70-130 cm tall, robust, branched, glabrous, grooved. Basal leaves shortly petiolate, broadly ovate, 14-28 × 7-17 cm, thin, both surfaces glabrous, abaxially with prominent veins, base cordate, margin slightly undulate, apex subacute; cauline leaves shortly petiolate, small; ocrea fugacious, membranous. Inflorescence paniculate, lax. Flowers bisexual. Pedicel filiform, 8-16 mm, slender, dilated upward, articulate near base. Inner tepals enlarged in fruit; valves broadly cordate, 5-7 × 6-8 mm, only 1 valve with a tubercle, net veined, base cordate, margin nearly entire, apex acuminate; tubercle elliptic, 2-3 mm. Achenes brownish, ovoid, trigonous, 2-3 mm, apex acuminate. Fl. May-Jun, fr. Jun-Jul.

Moist valleys, forest margins on mountain slopes; 1100-1900 m. Xinjiang (Tian Shan) [Afghanistan, Kazakhstan, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan; SW Asia].

One of us (Grabovskaya-Borodina) treats this as a synonym of Rumex paulsenianus K. H. Rechinger.