حماض (حُمَّاض)، حميض (حُمِّيض)

Rumex dentatus, belonging to subsect. Dentati Rechinger f. (K. H. Rechinger 1937), is an extremely variable species. In Eurasia and northern Africa it is represented by several distinct races, usually regarded as subspecies. Rechinger reported from North America (California and Oregon, mostly as a casual alien occuring in ballast grounds) only subsp. klotzschianus (Meisner) Rechinger f., which is native in southern and eastern Asia (China, India, Japan, Korea). J. E. Dawson (1979) also regarded this as the most common subspecies in North America. However, I believe most North American representatives of this aggregate belong to subsp. halacsyi (Rechinger f.) Rechinger f., which is native in the eastern Mediterranean region (Asia Minor), the Caucasus, southeastern Europe, and western and central Asia. This subspecies, sometimes recognized as R. halacsyi Rechinger f., differs from subsp. klotzschianus by its broader triangular (not rounded) inner tepals and longer teeth (to 3 mm). Unfortunately, subspecies of R. dentatus still are insufficiently understood even in Eurasia. It would be premature to assign most North American specimens to any infraspecific entity.

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.

Plants annual, rarely biennial, glabrous or indistinctly papillose especially on veins of leaf blades abaxially, with fusiform, vertical rootstock. Stems erect, often flex-uous in inflorescence, branched distal to middle, occasionally almost from base, 20-70(-80) cm. Leaves: ocrea deciduous or partially persistent at maturity; blade oblong, elliptic-lanceolate, or ovate-elliptic, 3-8(-12) × 2-5 cm, normally less than 4 times as long as wide, not coriaceous, base normally truncate or subcordate to weakly cordate, margins entire, flat to weakly undulate, occasionally slightly crisped, apex obtuse or subacute. Inflorescences terminal, occupying distal 1/ 2 of stem, usually lax and interrupted, broadly paniculate, branches usually ascending and straight. Pedicels articulated in proximal 1/ 3, filiform, 2-5 mm, articulation distinctly swollen. Flowers 10-20 in rather dense remote whorls; inner tepals ovate-triangular or deltoid, 3-5.5(-6) × 2-3 mm (excluding teeth), ca. 1.5 times as long as wide, base truncate, margins in most cases distinctly dentate, very rarely subentire, apex acute to subacute, straight, teeth 2-4(-5), normally at each side of margins, narrowly triangular, straight, 1-3(-5) mm, equaling or shorter than width of inner tepals; tubercles (1-)3, equal or subequal. Achenes dark reddish brown, 2-2.8 × 1.4-1.8 mm. 2n = 40.

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.

introduced; Alta., Ont.; Ariz., Calif., Mo., Oreg., Tex.; se Europe; tropical and subtropical Asia; n Africa; introduced elsewhere.

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].

Flowering late spring-summer.

Waste places, shores, cultivated fields; 0-300m.

Moist valleys, mountain slopes; sea level to 2500 m.

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.