Rumex hymenosepalus |
Rumex sibiricus |
|
---|---|---|
Arizona dock, canaigre, canaigre dock, cañaigre dock, wild-rhubarb |
Siberian dock, Siberian or Siberian willow dock |
|
Habit | Plants perennial, glabrous or indistinctly papillose-pubescent, with distinctly tuberous roots and short rhizomes. | Plants perennial, glabrous, with vertical rootstock. |
Stems | usually erect, rarely ascending, branched above middle, 25–90(–100) cm. |
usually ascending, occasionally erect, usually producing axillary shoots below 1st-order inflorescence, especially at proximal nodes, 15–40(–70) cm. |
Leaves | 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. |
blades linear-lanceolate or narrowly linear-lanceolate, 6–15 × 1–2(–2.5) mm, usually ca. 6–10 times as long as wide, widest near middle, thin, not coriaceous, base cuneate, margins entire, flat or undulate, apex acute. |
Inflorescences | terminal, occupying distal 1/2 of stem, narrowly paniculate, rarely simple. |
terminal and axillary, terminal usually occupying distal 1/5–1/3 of stem, rather dense or occasionally interrupted in proximal 1/2, usually broadly paniculate (branches simple or with few 2d-order branches). |
Pedicels | articulated near middle or in proximal 1/3, filiform, 5–15(–20) mm, articulation indistinct. |
articulated in proximal 1/3, filiform (but thickened distally), 1.5–3.5(–4) mm, not more than 2–2.5 times as long as inner tepals, articulation indistinctly swollen. |
Flowers | 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. |
10–20(–25) in whorls; inner tepals ovate or occasionally ovate-lanceolate, 2.5–3(–3.5) × 1.6–2.5 mm, base broadly cuneate or truncate, margins entire or indistinctly erose, apex obtuse or subacute; tubercles 3, equal or subequal, usually distinctly narrower and much shorter than inner tepals, smooth or weakly rugose. |
Achenes | brown or reddish brown, 4–5(–7) × 2.5–4.5(–5) mm. |
dark brown, occasionally dark reddish brown, 2–2.5 × 1–1.2 mm. |
2n | = 40. |
= 20. |
Rumex hymenosepalus |
Rumex sibiricus |
|
Phenology | Flowering spring. | Flowering late spring–summer. |
Habitat | Sandy and rocky places: plains, slopes, stream beds, alkaline soils | Sandy, gravelly, and clayey shores of rivers and streams, wet rocky and grassy slopes |
Elevation | 0-1700(-2000) m (0-5600(-6600) ft) | 0-1500 m (0-4900 ft) |
Distribution |
AZ; CA; CO; MT; NM; NV; OK; TX; UT; WY; Mexico (Baja California, Chihuahua)
|
AK; NT; YT; Asia (n Russian Far East including Kamchatka, Siberia) |
Discussion | 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 hultenii Tzvelev, a species closely related to R. sibiricus (it differs from the latter mostly by inner tepals without tubercles), was reported from Alaska by N. N. Tzvelev (1987b, 1989b). Rumex hultenii is reported to differ from R. utahensis by its narrower leaves, and from R. subarcticus by its smaller inner tepals and erect or ascending (not prostrate) habit, as well as by smaller inner tepals. Records of R. utahensis from Alaska may refer to R. hultenii. I have seen no reliable specimens from North America of R. hultenii and cannot confirm that it occurs in Alaska. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 515. | FNA vol. 5, p. 513. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Rumex | Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Axillares |
Sibling taxa | ||
Synonyms | R. arizonicus, R. hymenosepalus var. salinus, R. salinus, R. saxei | R. salicifolius var. angustifolius |
Name authority | Torrey: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 177. (1859) | Hultén: Kongl. Svenska Vetensk. Acad. Handl., ser. 3, 5(2): 48. (1928) |
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