Narrowleaf Dock

Within its native range Rumex stenophyllus is mostly confined to slightly saline coastal and alluvial (riparian) habitats. It has successfully colonized a wide range of ruderal and segetal habitats in both Europe and North America. Further spread of this species in the central and southwestern United States and southern Canada may be expected (D. Löve and J.-P. Bernard 1958). It was placed by K. H. Rechinger (1949) in subsect. Stenophylli Rechinger f.

According to J. K. Morton and J. M. Venn (1990), reports of Rumex stenophyllus from Ontario refer to the hybrid R. crispus × R. obtusifolius, but R. stenophyllus may be found in the province in the future. Rumex stenophyllus may be distinguished from that hybrid by its fertile fruits and more uniform inner tepals.

Herbs perennial. Roots vertical, large, to 1 cm in diam. Stems erect, 40-80(-120) cm tall, usually branched above, glabrous, grooved. Basal leaves shortly petiolate, lanceolate or narrowly lanceolate, 10-18 × 1.5-4 cm, glabrous or indistinctly papillose along veins below, base cuneate, margin crisped, occasionally nearly flat and entire, apex acute; cauline leaves shortly petiolate or nearly sessile, narrowly lanceolate, small; ocrea fugacious, membranous. Inflorescence paniculate, narrow. Flowers bisexual, dense. Pedicel slender, articulate below middle (in proximal third). Inner tepals enlarged in fruit; valves triangular, 3-4(-5) mm × ca. 3.5 mm, all valves with narrowly ovate tubercles, base truncate to indistinctly cordate, margin denticulate, apex acute; denticles 0.5-1.5 mm, 4-10 at each side. Achenes brown, shiny, ellipsoid, 2.5-3 mm, sharply trigonous, base narrow, apex acute. Fl. May-Jun, fr. Jun-Aug. 2n = 20, 22, 60.

Plants perennial, glabrous or very indistinctly papillose normally only on veins of leaf blades abaxially, with fusiform, vertical rootstock. Stems erect, branched distal to middle, 40-80(-130) cm. Leaves: ocreae usually deciduous, rarely partially persistent at maturity; blade oblong-lanceolate, lanceolate, or narrowly lanceolate, normally 15-25(-30) × 2-7 cm, base cuneate or truncate, margins entire or irregularly denticulate, usually crisped and undulate, or, occasionally, flat, apex acute or subobtuse. Inflorescences terminal, occupying distal 2 of stem, dense or interrupted at base, narrowly paniculate, branches usually straight or occasionally arcuate. Pedicels articulated in proximal 3, filiform, 3-8 mm, articulation distinctly swollen. Flowers 20-25 in whorls; inner tepals orbiculate-ovate or occasionally ovate-deltoid, 3.5-5 × 3-5 mm, base truncate or slightly cordate, margins denticulate, apex acute or subacute, teeth 4-10 at each side, 0.2-1.5 mm; tubercles normally 3, equal or subequal, less than 2 times as wide as inner tepals. Achenes usually reddish brown or dark brown, 2-2.5(-3) × 1-1.5 mm. 2n = 60.

Heilongjiang, Jilin, Nei Mongol, Xinjiang [Kazakhstan, Kyrgyzstan, Mongolia, Russia; Europe].

introduced; Alta., Man., Ont., Que., Sask.; Calif., Colo., Iowa, Kans., Minn., Mo., Mont., Nebr., Nev., N.Mex., N.Dak., Okla., S.C., S.Dak., Utah, Wash., Wyo.; c, se Europe; c Asia (s Siberia).

Flowering late spring-early fall.

Water sides, field margins, moist valleys; 200-1200 m.

Waste places, roadsides, fields, meadows, swamps and marshes, shores, saline soils; 0-1600m.

Rumex odontocarpus Sandor ex Borbás; R. stenophyllus var. ussuriensis (Losinskaja) Kitagawa; R. ussuriensis Losinskaja.

Rumex alluvius F. C. Gates & McGregor; R. crispus Linnaeus var. dentatus Schur; R. obtusifolius Linnaeus var. cristatus Neilreich; R. odontocarpus Sandor ex Borbás

Rumex stenophyllus is a species of flowering plant in the knotweed family known by the common name narrow-leaf dock. It is native to Eurasia and it can be found in parts of North America as an introduced species and roadside weed. It grows in moist and wet habitat, often in areas with saline soils. It is a perennial herb producing an erect stem from a thick taproot, usually measuring 40 to 80 centimeters tall, but known to well exceed one meter. The leaves are up to 30 centimeters long and are generally lance-shaped with curled edges. The inflorescence is an interrupted series of clusters of flowers with 20 to 25 in each cluster, each flower hanging from a pedicel. The flower has usually six tepals, the inner three of which are largest, triangular and edged with teeth, and bearing tubercles.