Description from Flora of China
Rumex dentatus subsp. halacsyi (K. Rechinger) K. H. Rechinger; R. dentatus subsp. klotzschianus (Meisner) K. H. Rechinger; R. ×halacsyi K. Rechinger; R. klotzschianus Meisner; R. nipponicus Franchet & Savatier.
Herbs annual, rarely biennial. Stems erect, 30-70 cm tall, branched from base, grooved; branches ascending to nearly divaricate, glabrous. Lower leaves: petiole 3-5 cm; leaf blade oblong to narrowly elliptic, 4-12 × 1.5-3 cm, both surfaces glabrous, or papillose along veins below, base rounded, truncate, or subcordate, margin slightly undulate, apex obtuse or acute; cauline leaves smaller; ocrea fugacious, membranous. Inflorescence racemose, several racemes aggregated and panicle-like. Flowers bisexual. Pedicel articulate below middle (in proximal third). Outer tepals elliptic, ca. 2 mm; inner tepals enlarged in fruit; valves triangular-ovate, 4-5 × 2.5-3 mm, all valves with tubercles 1.5-2 mm (in some infraspecific taxa of R. dentatus only 1 or 2 valves with tubercles), conspicuously net veined, base rounded, each margin with 2-4 teeth, apex acute to subacute; teeth 1.5-2 mm. Achenes yellow-brown, shiny, ovoid, sharply trigonous, 2-2.5 mm, base narrow, apex acute. Fl. May-Jun, fr. Jun-Jul. 2n = 40.
Rumex dentatus is an extremely variable species represented in N Africa, Asia, and Europe by several quite distinct races, recognized taxonomically mostly as subspecies. A taxon native mostly to E and S Asia (China, India, Japan, and Korea) is usually recognized as R. dentatus subsp. klotzschianus. Rumex dentatus subsp. halacsyi (R. ×halacsyi ) is native to the E Mediterranean region, the Caucasus, SE Europe, and parts of C and SW Asia, and probably also occurs in China. This subspecies differs from subsp. klotzschianus in having broader, triangular (not rounded) valves, and longer teeth (to 3 mm). However, subspecies of R. dentatus are still insufficiently understood taxonomically and insufficiently delimited geographically.
Moist valleys, mountain slopes; sea level to 2500 m. Anhui, Fujian, Gansu, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Taiwan, Yunnan, Zhejiang [Afghanistan, India, Kazakhstan, Kyrgyzstan, Nepal, Russia; N Africa, SE Europe].