Rumex obtusifolius |
Rumex pycnanthus |
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bitter dock, broad-leaf dock, broad-leaf or broadleaf or bitter dock, patience a feuilles obtuses |
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Habit | Plants perennial, glabrous or ± papillose especially on veins of leaf blades abaxially, with fusiform, vertical rootstock. | Plants perennial, glabrous or indistinctly papillose-pubescent, with fusiform or creeping horizontal rhizome. |
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 above middle (only in inflorescence), 60–100 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. |
ocreae deciduous or partially persistent at maturity; blade normally oblong-lanceolate, 20–45 × 8–10 cm, normally more than 3 times as long as wide, base broadly cuneate, truncate, or weakly cordate, margins entire, flat or indistinctly crisped, apex obtuse or broadly acute. |
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 of stem, often dense, narrowly paniculate. |
Pedicels | articulated in proximal 1/3 or rarely near middle, filiform, 2.5–8.5(–10) mm, articulation distinctly swollen. |
articulated in proximal 1/2, occasionally almost near base, filiform, 3–11 mm, articulation indistinct or weakly evident. |
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. |
10–20 in whorls; inner tepals ovate-deltoid or ovate-triangular, 4–7 × 3–5 mm, widest at or near base, base truncate or weakly emarginate, margins erose to minutely dentate at least near base, apex narrowly acute; tubercles absent. |
Achenes | brown to reddish brown, 2–2.7 × 1.2–1.7 mm. |
deep brown to reddish brown, 3–4 × 1.5–2.2 mm. |
2n | = 40. |
= 120. |
Rumex obtusifolius |
Rumex pycnanthus |
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Phenology | Flowering late spring–early fall. | Flowering late spring–summer. |
Habitat | Waste places, roadsides, fields, shores, meadows, wet woods, swamps | Along streams and rivers in montane, subalpine, and alpine zones |
Elevation | 0-2300 m (0-7500 ft) | 1700-3000 m (5600-9800 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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CO; UT |
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 pycnanthus was reported (as R. subalpinus M. E. Jones) from White Pine County, Nevada (Mont E. Lewis 1973) and may occur in that state; according to J. T. Kartesz (1987, vol. 1), that record was based on misidentification of R. californicus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 526. | FNA vol. 5, p. 516. |
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. subalpinus, R. densiflorus subsp. pycnanthus |
Name authority | Linnaeus: Sp. Pl. 1: 335. (1753) | Rechinger f.: Repert. Spec. Nov. Regni Veg. 38: 372. (1935) |
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