Rumex mexicanus |
Rumex dentatus |
|
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Mexican dock, Mexican willow, Mexican willow or dock |
lengua de vaca, tooth dock, tooth or dentate or Indian dock |
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Habit | Plants perennial, glabrous; with vertical rootstock, occasionally with short, creeping rhizomes. | Plants annual, rarely biennial, glabrous or indistinctly papillose especially on veins of leaf blades abaxially, with fusiform, vertical rootstock. |
Stems | erect or ascending, usually producing axillary shoots below 1st-order inflorescence or at proximal nodes, 30–60(–90) cm. |
erect, often flexuous in inflorescence, branched distal to middle, occasionally almost from base, 20–70(–80) cm. |
Leaves | blades light green to yellowish green, linear-lanceolate, occasionally lanceolate, 6–14 × 1–3.5(–4) cm, usually ca. 5–7 times as long as wide, widest near middle, thin, not coriaceous, base cuneate, margins entire, flat or undulate, apex acute or attenuate. |
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 and axillary, terminal usually occupying distal 1/5–1/3 of stem, rather dense or interrupted in proximal 1/2, usually broadly paniculate (branches simple or with few 2d-order branches). |
terminal, occupying distal 1/2 of stem, usually lax and interrupted, broadly paniculate, branches usually ascending and straight. |
Pedicels | articulated in proximal 1/3 or almost near base, filiform (thickened distally), 4–7 mm, not more than 2–2.5 times as long as inner tepals, articulation indistinctly swollen. |
articulated in proximal 1/3, filiform, 2–5 mm, articulation distinctly swollen. |
Flowers | 10–20 in whorls; inner tepals broadly ovate-triangular, occasionally broadly triangular, 3.5–4.5(–5) × 3.5–4(–5) mm, base truncate or indistinctly cordate, margins entire or indistinctly erose, apex obtuse or subacute; tubercles 3, equal or subequal (much narrower than inner tepals). |
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 | brown or dark reddish brown, 2–3 × 1.5–2 mm. |
dark reddish brown, 2–2.8 × 1.4–1.8 mm. |
2n | = 40. |
= 40. |
Rumex mexicanus |
Rumex dentatus |
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Phenology | Flowering spring–early summer. | Flowering late spring–summer. |
Habitat | Shores of streams and rivers, wet meadows | Waste places, shores, cultivated fields |
Elevation | 1000 m (3300 ft) | 0-300 m (0-1000 ft) |
Distribution |
NM; Mexico
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AZ; CA; MO; OR; TX; AB; ON; se Europe; tropical and subtropical Asia; n Africa [Introduced in North America; introduced elsewhere]
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Discussion | Some authors recognize Rumex mexicanus in the broad sense, including in it many other taxa treated here as separate entities. For consistency, the entities of the R. salicifolius aggregate that are recognized herein are kept separate pending additional taxonomic research. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 511. | FNA vol. 5, p. 527. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Axillares | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Rumex |
Sibling taxa | ||
Name authority | Meisner: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 45. (1856) | Linnaeus: Mant. Pl., 226. (1771) |
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