Rumex hymenosepalus
Rumex obtusifolius
Arizona dock, canaigre, canaigre dock, cañaigre dock, wild-rhubarb
bitter dock, broad-leaf dock, broad-leaf or broadleaf or bitter dock, patience a feuilles obtuses
usually erect, rarely ascending, branched above middle, 25–90(–100) cm.
erect, branched distal to middle or occasionally in distal 2/3, often with few flowering stems from rootstock, 60–120(–150) cm.
ocrea prominent and persistent at maturity, whitish or silvery white, membranous;
blade oblong, oblong-elliptic, or obovate-lanceolate, (5–)8–30 × 2–8(–12) cm, base cuneate or narrowly cuneate, margins entire, flat or indistinctly crisped, apex acute or acuminate, rarely obtuse.
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.
terminal, occupying distal 1/2 of stem, narrowly paniculate, rarely simple.
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.
articulated near middle or in proximal 1/3, filiform, 5–15(–20) mm, articulation indistinct.
articulated in proximal 1/3 or rarely near middle, filiform, 2.5–8.5(–10) mm, articulation distinctly swollen.
5–20 in whorls;
inner tepals oblong-cordate or orbiculate-cordate, 11–16 × 9.5–14 mm, base sinuate or emarginate, margins entire, rarely with few extremely small denticles at base, apex obtuse or subacute;
tubercles absent.
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.
brown or reddish brown, 4–5(–7) × 2.5–4.5(–5) mm.
brown to reddish brown, 2–2.7 × 1.2–1.7 mm.
= 40.
= 40.
Rumex hymenosepalus
Rumex obtusifolius
Rumex hymenosepalus is the only species of subsect. Hymenosepali Rechinger f.
Two varieties have been recognized. The typical variety has achenes 5 mm and ovate-elliptic or oblong-cordate inner tepals with a subacute apex. Variety salinus (A. Nelson) Rechinger f. has larger achenes (to 7 mm) and almost orbiculate inner tepals with an obtuse apex.
Rumex hymenosepalus was reported also from Montana (J. E. Dawson 1979), but no exact localities were given.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
SW CO Wildflowers- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
