The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

common sheep sorrel, field sorrel, oseille, petite oseille, red sorrel, sheep dock, sheep sorrel, sour weed, sûrette

subarctic or subarctic willow dock

Habit Plants perennial, glabrous, with vertical rootstock and/or creeping rhizomes. Plants perennial, glabrous, with vertical rootstock.
Stems

erect or ascending, several from base, branched in distal 1/2 (in inflorescence), 10–40(–45) cm;

shoots variable.

usually procumbent, rarely ascending, usually producing axillary shoots below 1st-order inflorescence or at proximal nodes, 30–60 cm.

Leaves

ocrea brownish at base, silvery and lacerated in distal 1/2;

blade normally obovate-oblong, ovate-lanceolate, lanceolate-elliptic, or lanceolate, occasionally, linear-lanceolate to almost linear, 2–6 × 0.3–2 cm, base hastate (with spreading, entire or sometimes multifid, dissected lobes), occasionally without evident lobes, then base broadly cuneate, margins entire, flat or nearly so, apex acute or obtuse.

blades narrowly linear-lanceolate, 6–17 × 1–3 cm, usually ca. 7–10 times as long as wide, widest near middle, usually thick, not coriaceous or subcoriaceous, base cuneate, margins entire, usually strongly undulate and/or crenulate, apex acute.

Inflorescences

terminal, usually occupying distal 1/2–2/3 of stem, usually lax and interrupted to top, broadly or narrowly paniculate.

terminal and axillary, terminal usually occupying distal 1/5–1/3 of stem, rather dense towards apex, distinctly interrupted in proximal 1/2, usually broadly paniculate (branches almost at right angles to main axis, simple or with few 2d-order branches).

Pedicels

1–3 mm.

articulated in proximal 1/3, filiform, 4–7 mm, not more than 2–2.5 times as long as inner tepals, articulation slightly swollen.

Flowers

(3–)5–8(–10) in whorls;

inner tepals not or slightly enlarged, normally 1.2–1.7(–2) × 0.5–1.3 mm (free wing absent or barely visible), base cuneate, apex obtuse or subacute.

10–20 in whorls;

inner tepals, broadly deltoid or deltoid-ovate, 3–4 × 3.2–4(–4.5) mm, base truncate, margins entire or indistinctly crenulate, apex obtuse or subacute;

tubercles absent, rarely small and indistinct.

Achenes

brown or dark brown, 0.9–1.5 × 0.6–0.9 mm.

brown or dark reddish brown, 2–3 × 1.5–2 mm.

2n

= 14, 28, 42.

= 20.

Rumex acetosella

Rumex subarcticus

Phenology Flowering spring–summer. Flowering early summer.
Habitat Roadsides, cultivated fields, waste places, disturbed areas, lawns, meadows, railroad gravels, sandy and muddy shores: usually in acidic soils Mostly coastal and alluvial habitats: sea beaches, shores of rivers and streams, wet meadows
Elevation 0-2700 m (0-8900 ft) 0-200 m (0-700 ft)
Distribution
from FNA
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; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; ON; PE; QC; SK; YT; SPM; Greenland; Europe; w Asia [Introduced in North America; introduced almost worldwide]
[WildflowerSearch map]
[BONAP county map]
from FNA
NU; QC
[BONAP county map]
Discussion

Rumex acetosella in the broad sense is an extremely variable and taxonomically complicated polyploid complex, which includes diploids, tetraploids, hexaploids, and octoploids. This complex (excluding more distantly related arctic-montane R. graminifolius and its allies) probably originated and developed mostly in southern Europe and southwestern Asia. Some races of R. acetosella now are distributed almost worldwide as introduced and often completely naturalized aliens.

Á. Löve (1941, 1983) assumed that in this group chromosome numbers are strictly correlated with morphology. In his opinion, every chromosome race represents a distinct species: diploid Rumex angiocarpus Murbeck [= Acetosella angiocarpa (Murbeck) Á. Löve]; tetraploid R. multifidus Linnaeus [= R. tenuifolius (Wallroth) Á. Löve = Acetosella multifida (Linnaeus) Á. Löve]; hexaploid R. acetosella in the narrow sense [= A. vulgaris (W. D. J. Koch) Fourreau, with gymnocarpous A. vulgaris subsp. vulgaris and angiocarpous A. vulgaris subsp. pyrenaica (Pourret ex Lapeyrouse) Á. Löve]; hexaploid R. graminifolius Rudolph ex Lambert [= A. graminifolia (Rudolph ex Lambert) Á. Löve]. However, the distribution given by Löve for these taxa seems unnatural. Studies by J. C. M. den Nijs and collaborators (den Nijs 1974, 1976, 1984; den Nijs and T. Panhorst 1980; den Nijs et al. 1980, 1985; see also W. Harris 1969, 1973) indicate that the situation is more complicated. They postulated the development of two major evolutionary lines into two ploidy complexes: a primary western Mediterranean one and a secondary eastern Mediterranean one. According to this scheme, polyploid races independently and spontaneously emerged (and still are emerging) within different ancestral populations.

The most widespread, almost cosmopolitan race, presumably native to the southwestern Mediterranean region, including southwestern and Atlantic Europe, which is common in North America, is characterized by a hexaploid chromosome set (2n = 42), nonmultifid lateral lobes of basal leaves, and angiocarpy (fruits are not easily separable from accrescent inner tepals). It was commonly and erroneously referred to as Rumex angiocarpus Murbeck, or R. acetosella subsp. angiocarpus (Murbeck) Murbeck. According to J. R. Akeroyd (1991), who in general followed the taxonomic revision of the group by J. C. M. den Nijs (1984), the correct name for this taxon is R. acetosella subsp. pyrenaicus (Pourret ex Lapeyrouse) Akeroyd (=Acetosella vulgaris subsp. pyrenaica (Pourret ex Lapeyrouse) Á. Löve). Gymnocarpous nonmultifid and multifid forms (R. acetosella subsp. acetosella and R. acetosella subsp. acetoselloides (Balansa) den Nijs, respectively) also occur in North America, but evidently rarely. The distributions of subspecies of R. acetosella in North America are poorly known. Keys and detailed descriptions for the subspecies were provided by den Nijs and Akeroyd. However, the tempting simplicity of the keys is somewhat suspicious. The alternative point of view (and an alternative key) may be found in Á. Löve (1983).

Rumex acetosella subsp. arenicola Mäkinen ex Elven was recently described from Greenland and reported for Scandinavia and arctic Russia (R. Elven et al. 2000). This entity seems to be morphologically transitional toward Rumex graminifolius (see discussion under that species below). According to Elven et al., it differs from other infraspecific entities of R. acetosella in having the following characters: leaves usually without basal lobes (as in R. graminifolius), with revolute margins; inflorescence sparsely branched; tepals and pedicels densely covered with red papillae (as in R. graminifolius). From R. graminifolius and related taxa (R. beringensis and R. krausei) it can be distinguished by narrower inner tepals (similar in size to those in other subspecies of R. acetosella). The distribution of subsp. arenicola and its relations to other taxa are in need of further study.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Some specimens of Rumex subarcticus have well-developed tubercles similar to those of R. pallidus (N. M. Sarkar 1958), to which it is closely related and of which it may be regarded as a northwestern subspecies or variety (see Á. Löve 1986).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 498. FNA vol. 5, p. 513.
Parent taxa Polygonaceae > subfam. Polygonoideae > Rumex > subg. Acetosella Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Axillares
Sibling taxa
R. acetosa, R. alpinus, R. altissimus, R. arcticus, R. beringensis, R. britannica, R. brownii, R. bucephalophorus, R. californicus, R. chrysocarpus, R. confertus, R. conglomeratus, R. crassus, R. crispus, R. cristatus, R. cuneifolius, R. densiflorus, R. dentatus, R. ellipticus, R. fascicularis, R. floridanus, R. fueginus, R. graminifolius, R. hastatulus, R. hesperius, R. hymenosepalus, R. kerneri, R. krausei, R. lacustris, R. lapponicus, R. longifolius, R. maritimus, R. mexicanus, R. nematopodus, R. obovatus, R. obtusifolius, R. occidentalis, R. orthoneurus, R. pallidus, R. palustris, R. paraguayensis, R. patientia, R. paucifolius, R. persicarioides, R. praecox, R. pseudonatronatus, R. pulcher, R. pycnanthus, R. salicifolius, R. sanguineus, R. sibiricus, R. spiralis, R. stenophyllus, R. subarcticus, R. thyrsiflorus, R. tomentellus, R. transitorius, R. triangulivalvis, R. utahensis, R. venosus, R. verticillatus, R. violascens
R. acetosa, R. acetosella, R. alpinus, R. altissimus, R. arcticus, R. beringensis, R. britannica, R. brownii, R. bucephalophorus, R. californicus, R. chrysocarpus, R. confertus, R. conglomeratus, R. crassus, R. crispus, R. cristatus, R. cuneifolius, R. densiflorus, R. dentatus, R. ellipticus, R. fascicularis, R. floridanus, R. fueginus, R. graminifolius, R. hastatulus, R. hesperius, R. hymenosepalus, R. kerneri, R. krausei, R. lacustris, R. lapponicus, R. longifolius, R. maritimus, R. mexicanus, R. nematopodus, R. obovatus, R. obtusifolius, R. occidentalis, R. orthoneurus, R. pallidus, R. palustris, R. paraguayensis, R. patientia, R. paucifolius, R. persicarioides, R. praecox, R. pseudonatronatus, R. pulcher, R. pycnanthus, R. salicifolius, R. sanguineus, R. sibiricus, R. spiralis, R. stenophyllus, R. thyrsiflorus, R. tomentellus, R. transitorius, R. triangulivalvis, R. utahensis, R. venosus, R. verticillatus, R. violascens
Synonyms Acetosa acetosella, Acetosa hastata, Acetosa vulgaris, R. acetosella var. vulgaris R. pallidus subsp. subarcticus
Name authority Linnaeus: Sp. Pl. 1: 338. (1753) Lepage: Naturaliste Canad. 82: 191. (1955)
Web links