Rumex mexicanus |
Rumex stenophyllus |
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Mexican dock, Mexican willow, Mexican willow or dock |
narrow-leaf dock |
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Habit | Plants perennial, glabrous; with vertical rootstock, occasionally with short, creeping rhizomes. | Plants perennial, glabrous or very indistinctly papillose normally only 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, branched distal to middle, 40–80(–130) 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. |
ocreae usually deciduous, rarely partially persistent at maturity; blade oblong-lanceolate, lanceolate, or narrowly lanceolate, normally 15–25(–30) × 2–7 cm, base cuneate or truncate, margins entire or irregularly denticulate, usually crisped and undulate, or, occasionally, flat, apex acute or subobtuse. |
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, dense or interrupted at base, narrowly paniculate, branches usually straight or occasionally arcuate. |
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, 3–8 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). |
20–25 in whorls; inner tepals orbiculate-ovate or occasionally ovate-deltoid, 3.5–5 × 3–5 mm, base truncate or slightly cordate, margins denticulate, apex acute or subacute, teeth 4–10 at each side, 0.2–1.5 mm; tubercles normally 3, equal or subequal, less than 2 times as wide as inner tepals. |
Achenes | brown or dark reddish brown, 2–3 × 1.5–2 mm. |
usually reddish brown or dark brown, 2–2.5(–3) × 1–1.5 mm. |
2n | = 40. |
= 60. |
Rumex mexicanus |
Rumex stenophyllus |
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Phenology | Flowering spring–early summer. | Flowering late spring–early fall. |
Habitat | Shores of streams and rivers, wet meadows | Waste places, roadsides, fields, meadows, swamps and marshes, shores, saline soils |
Elevation | 1000 m (3300 ft) | 0-1600 m (0-5200 ft) |
Distribution |
NM; Mexico
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CA; CO; IA; KS; MN; MO; MT; ND; NE; NM; NV; OK; SC; SD; UT; WA; WY; AB; MB; ON; QC; SK; c Europe; se Europe; c Asia (s Siberia) [Introduced in North America]
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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.) |
Within its native range Rumex stenophyllus is mostly confined to slightly saline coastal and alluvial (riparian) habitats. It has successfully colonized a wide range of ruderal and segetal habitats in both Europe and North America. Further spread of this species in the central and southwestern United States and southern Canada may be expected (D. Löve and J.-P. Bernard 1958). It was placed by K. H. Rechinger (1949) in subsect. Stenophylli Rechinger f. According to J. K. Morton and J. M. Venn (1990), reports of Rumex stenophyllus from Ontario refer to the hybrid R. crispus × R. obtusifolius, but R. stenophyllus may be found in the province in the future. Rumex stenophyllus may be distinguished from that hybrid by its fertile fruits and more uniform inner tepals. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 511. | FNA vol. 5, p. 523. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Axillares | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Rumex |
Sibling taxa | ||
Synonyms | R. alluvius, R. crispus var. dentatus, R. obtusifolius var. cristatus, R. odontocarpus | |
Name authority | Meisner: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 45. (1856) | Ledebour: Fl. Altaica 2: 58. (1830) |
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