Rumex obtusifolius |
Rumex kerneri |
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bitter dock, broad-leaf dock, broad-leaf or broadleaf or bitter dock, patience a feuilles obtuses |
Kerner's dock |
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Habit | Plants perennial, glabrous or ± papillose especially on veins of leaf blades abaxially, with fusiform, vertical rootstock. | Plants perennial, distinctly papillose especially or almost exclusively on veins of leaf blades abaxially, with fusiform, vertical rootstock. |
Stems | erect, branched distal to middle or occasionally in distal 2/3, often with few flowering stems from rootstock, 60–120(–150) cm. |
erect, branched from above middle or in distal 2/3, 50–100(–150) cm. |
Leaves | ocrea deciduous to partially persistent at maturity; blade oblong to ovate-oblong, sometimes broadly ovate, 20–40 × 10–15 cm, usually less than 4 times as long as wide, base normally distinctly cordate, occasionally rounded, rarely truncate, margins normally entire, flat or undulate, rarely slightly crisped, apex obtuse or subacute. |
ocrea deciduous or partially persistent at maturity; blade broadly lanceolate to oblong-lanceolate, normally 15–25 × 5–9 cm, base truncate or slightly cordate, margins entire, undulate or weakly crisped, occasionally flat, apex acute or attenuate. |
Inflorescences | terminal, occupying distal 2/3 of stem, usually lax and interrupted, narrowly or broadly paniculate, branches usually forming angle of 30–45° with 1st-order stem. |
terminal, occupying distal 1/2–2/3 of stem, normally dense or interrupted near base, broadly paniculate (branches mostly simple or nearly so), branches usually straight or arcuate, rarely indistinctly flexuous. |
Pedicels | articulated in proximal 1/3 or rarely near middle, filiform, 2.5–8.5(–10) mm, articulation distinctly swollen. |
articulated near middle, filiform, 6–12 mm, articulation distinctly swollen. |
Flowers | 10–25 in lax whorls; inner tepals ovate-triangular, deltoid or, occasionally, lingulate, 3–6 × 2–3.5 mm (excluding teeth), ca. 1.5–2 times as long as wide, base truncate, margins usually distinctly dentate, rarely subentire, apex obtuse to subacute, straight, teeth 2–5, normally at each side of margin, short-subulate or triangular-subulate, straight, 0.5–1.8 mm, or shorter than width of inner tepals; tubercle usually 1, sometimes 3, then 1 distinctly larger, smooth. |
15–20 in whorls; inner tepals orbiculate, 6–8(–9) × 6–7.5(–8) mm, base usually distinctly cordate, margins entire or subentire near apex, denticulate or dentate near base, apex acute or subacute, teeth to 0.5 mm; tubercle normally 1 (rarely 3, then distinctly unequal), less than 2 times as wide as inner tepals. |
Achenes | brown to reddish brown, 2–2.7 × 1.2–1.7 mm. |
dark brown or brown, 2.5–3.3 × 1.8–2.3 mm. |
2n | = 40. |
= 80. |
Rumex obtusifolius |
Rumex kerneri |
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Phenology | Flowering late spring–early fall. | Flowering late spring–early summer. |
Habitat | Waste places, roadsides, fields, shores, meadows, wet woods, swamps | Ruderal habitats: roadsides, waste places |
Elevation | 0-2300 m (0-7500 ft) | 0-500 m (0-1600 ft) |
Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; TN; TX; UT; VA; VT; WA; WI; WV; BC; NB; NF; NS; ON; PE; QC; SPM; Greenland; Europe; w Asia [Introduced in North America; introduced elsewhere]
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CA; se Europe [Introduced in North America] |
Discussion | Rumex obtusifolius, a member of subsect. Obtusifolii Rechinger f. (K. H. Rechinger 1937), is a polymorphic species represented in Eurasia by three or four rather distinct races often treated by European authors as subspecies or varieties. These taxa differ mostly in inner tepal dentation and geographic distribution. In North America the morphotypes often intergrade. In Eurasia this species is differentiated into predominantly western subsp. obtusifolius [including R. obtusifolius subsp. agrestis (Fries) Danser], eastern subsp. sylvestris (Wallroth) Rechinger f., intermediate central European subsp. transiens (Simonkai) Rechinger f., and montane subsp. subalpinus (Schur) Simonkai. Only subspp. obtusifolius and sylvestris occur in North America; the former seems to be more common. Subspecies obtusifolius differs from subsp. sylvestris in having larger and more prominently dentate inner tepals with one tubercle, or with three distinctly unequal tubercles; in subsp. sylvestris the teeth are usually less than 0.6 mm, developing only near the base of the inner tepals, and the tubercles often almost subequal. Rumex obtusifolius may be expected elsewhere in the Great Plains region of the United States and Canada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Rumex kerneri is known in North America only from California, where it occurs mostly in Santa Barbara and San Luis Obispo counties. It is closely related to and has been regarded as a subspecies of R. cristatus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 526. | FNA vol. 5, p. 521. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Rumex | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Rumex |
Sibling taxa | ||
Synonyms | R. crispatulus, R. rugelii | R. confertoides, R. cristatus subsp. kerneri |
Name authority | Linnaeus: Sp. Pl. 1: 335. (1753) | Borbás: Fl. Comit. Temesiensis, 60. (1884) |
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