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swamp dock

rumex occidental, western dock, western dock o n

Habit Plants perennial, glabrous or nearly so, with vertical rootstock. Plants perennial, glabrous or very indistinctly papillose, especially on veins of leaf blades abaxially, with fusiform, vertical or oblique rootstock.
Stems

erect or, rarely, ascending, simple or producing axillary shoots below 1st-order inflorescence or at proximal nodes, 40–100(–150) cm.

usually erect, branched from above middle or in distal 2/3, 50–100(–140) cm.

Leaves

blades with lateral veins forming angle of 45–60° with midvein, linear-lanceolate or lanceolate, 5–30(–40) × 1–5 cm, usually 5–7(–10) times as long as wide, normally rather thin or at most subcoriaceous, base narrowly cuneate, margins entire, flat or slightly undulate, apex acute or acuminate.

ocrea deciduous or partially persistent at maturity;

blade narrowly ovate-triangular, ovate-lanceolate, or oblong-lanceolate, normally 10–35 × 5–12 cm, base weakly to distinctly cordate, truncate, or rounded, margins entire, undulate or indistinctly crisped, apex acute or subacute, rarely obtuse.

Inflorescences

terminal and axillary, terminal usually occupying distal 1/3–1/2 of stem, usually lax, interrupted at least in basal 1/2, narrowly paniculate.

terminal, occupying distal 2/3 of stem, dense to interrupted, narrowly paniculate, often repeatedly branched (branches usually more than 7–8 cm).

Pedicels

articulated in proximal part, distinctly thickened distally, 10–17 mm, (2.5–)3–5 times as long as inner tepals, articulation distinctly or slightly swollen.

articulated in proximal 1/3, filiform, 5–13(–17) mm, normally not more than 2–2.5 times as long as inner tepals, articulation weakly evident, not swollen.

Flowers

10–15(–25) in remote whorls;

inner tepals ovate-triangular or ovate-deltoid, 3.5–5 × 2.5–4 mm, longer than wide or, very rarely, as long as wide, base truncate or rounded, margins entire or, rarely, very indistinctly erose, apex acute or subacute (then with broadly triangular-lingulate tip);

tubercles 3, equal or subequal, minutely punctate and/or transversely rugose (wrinkled) in proximal part.

mostly 12–25 in whorls;

inner tepals orbiculate, ovate, or broadly ovate-triangular, 5–10(–12) × 5–8(–11) mm, base truncate to weakly cordate, margins entire or subentire to very weakly erose, apex obtuse or subacute;

tubercles absent.

Achenes

brown or dark brown, 2.3–3.1 × 1.6–2.2 mm.

reddish brown, 3–4.5(–4.8) × 1.5–2.5 mm.

2n

= 60.

= 120.

Rumex verticillatus

Rumex occidentalis

Phenology Flowering spring–early summer. Flowering late spring–summer.
Habitat Swamps, bogs, marshes, wet meadows, irrigation ditches, wet alluvial woods Wet meadows, bogs, marshes, river banks, shallow water, other wet habitats
Elevation 0-800 m (0-2600 ft) 0-2500(-3000) m (0-8200(-9800) ft)
Distribution
from FNA
AL; AR; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; NE; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; ON; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AZ; CA; CO; IA; ID; ME; MN; MT; ND; NM; NV; OR; SD; UT; VT; WA; WY; AB; BC; MB; NF; NS; NT; ON; QC; SK; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

Reports of Rumex verticillatus for New Mexico (W. C. Martin and C. R. Hutchins 1980) need confirmation. The species was reported erroneously from Colorado (S. L. O’Kane et al. 1988) as a result of misidentification of R. fueginus (see W. A. Weber and R. C. Wittmann 1992).

I have not seen specimens of Rumex verticillatus from Delaware, Maine, New Hampshire, and New Jersey, but the species probably occurs in those states.

The following two species are closely related to Rumex verticillatus and sometimes treated as subspecies of it.

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

In the nineteenth century, Rumex occidentalis commonly was misidentified as R. aquaticus, R. longifolius, or R. domesticus.

All of the species of subsect. Aquatici Rechinger f., represented in North America by Rumex occidentalis, R. arcticus, R. nematopodus, and R. tomentellus, form a taxonomically complex aggregate with poorly delimited, often intergrading species. Extremes are evidently distinct (e.g., R. arcticus and R. tomentellus). The taxonomy and distribution of members of this aggregate are still insufficiently known. Some authors prefer to treat all or most of these taxa as subspecies or varieties of R. aquaticus in the broad sense. From my point of view, this does not promote a better understanding of their variability and relationships.

A number of segregate species have been described and recognized in regional floras in North America. In most cases the features upon which these species are based intergrade. One of the most widely recognized segregates is Rumex fenestratus Greene emend. Rechinger f. [R. aquaticus subsp. fenestratus (Greene) Hultén, R. occidentalis S. Watson subsp. fenestratus (Greene) Hultén], which, according to K. H. Rechinger (1937), may be distinguished mostly by larger and more cordate fruiting inner tepals (more than 7 mm in R. fenestratus, usually less than 7 mm in R. occidentalis), and larger achenes (3 mm, and more than 3.5 mm, respectively). The morphotype of R. fenestratus occurs mostly along the Pacific coast from central western California to Alaska. Plants with large fruiting inner tepals [known as R. fenestratus var. labradoricus Rechinger f. or R. occidentalis var. labradoricus (Rechinger f.) Lepage] occur also in eastern Canada (Newfoundland and Quebec). In this treatment, I follow the taxonomic decision by J. E. Dawson (1979), who carefully analyzed the clinal variability of the R. occidentalis aggregate. However, R. fenestratus probably deserves recognition at least as a subspecies of R. occidentalis, but its taxonomic status needs additional investigation.

Rumex occidentalis was reported also from New Brunswick (which seems to be a rather natural extension of its range); however, the present status of the species in that province is uncertain.

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

Source FNA vol. 5, p. 505. FNA vol. 5, p. 518.
Parent taxa Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Axillares Polygonaceae > subfam. Polygonoideae > Rumex > subg. Rumex > sect. Rumex
Sibling taxa
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. subarcticus, R. thyrsiflorus, R. tomentellus, R. transitorius, R. triangulivalvis, R. utahensis, R. venosus, 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. 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
Synonyms R. aquaticus subsp. fenestratus, R. aquaticus subsp. occidentalis, R. bakeri, R. fenestratus, R. fenestratus var. labradoricus, R. gracilipes, R. occidentalis subsp. fenestratus, R. occidentalis var. labradoricus
Name authority Linnaeus: Sp. Pl. 1: 334. (1753) S. Watson: Proc. Amer. Acad. Arts 12: 253. (1877)
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