Rumex mexicanus
Rumex lacustris
Mexican dock, Mexican willow, Mexican willow or dock
lake dock, lake willow dock
erect or ascending, usually producing axillary shoots below 1st-order inflorescence or at proximal nodes, 30–60(–90) cm.
erect, ascending, or submerged and/or floating (in aquatic forms), usually producing numerous axillary shoots below 1st-order inflorescence or at proximal nodes (especially in aquatic plants), 40–70(–90) cm.
blades light green to yellowish green, linear-lanceolate, occasionally lanceolate, 6–14 × 1–3.5(–4) cm, usually ca. 5–7 times as long as wide, widest near middle, thin, not coriaceous, base cuneate, margins entire, flat or undulate, apex acute or attenuate.
blades very variable, in aquatic submerged forms usually ovate-lanceolate to lanceolate, glabrous or nearly so; in terrestrial forms lanceolate, papillose-pubescent abaxially, (2–)3–7 × (0.5–)1–3 cm, usually ca. 3.5–5 times as long as wide, widest near middle, thin or occasionally subcoriaceous in terrestrial plants, base cuneate, margins entire, flat or undulate, apex acute or subobtuse.
terminal and axillary, terminal usually occupying distal 1/5–1/3 of stem, rather dense or interrupted in proximal 1/2, usually broadly paniculate (branches simple or with few 2d-order branches).
terminal and axillary, terminal usually occupying distal 1/5 or less of stem, dense or interrupted in proximal 1/2 usually narrowly paniculate (branches simple and comparatively short).
articulated in proximal 1/3 or almost near base, filiform (thickened distally), 4–7 mm, not more than 2–2.5 times as long as inner tepals, articulation indistinctly swollen.
articulated in proximal 1/2, or almost near middle, filiform (slightly thickened distally), 2.5–4(–6) mm, subequal to inner tepals or at most 2 times longer, articulation indistinctly swollen.
10–20 in whorls;
inner tepals broadly ovate-triangular, occasionally broadly triangular, 3.5–4.5(–5) × 3.5–4(–5) mm, base truncate or indistinctly cordate, margins entire or indistinctly erose, apex obtuse or subacute;
tubercles 3, equal or subequal (much narrower than inner tepals).
10–20 in whorls;
inner tepals ovate or elliptic, occasionally elliptic-triangular, 2–2.5(–3) × 1–1.5(–2) mm, base truncate or broadly rounded-cuneate, margins entire or very indistinctly erose, apex subacute or obtuse;
tubercles 3, equal or subequal (much narrower than inner tepals), smooth or slightly verrucose.
brown or dark reddish brown, 2–3 × 1.5–2 mm.
brown or dark reddish brown, 1.5–2.2 × 0.8–1.2 mm.
= 40.
= 20.
Rumex mexicanus
Rumex lacustris
Some authors recognize Rumex mexicanus in the broad sense, including in it many other taxa treated here as separate entities. For consistency, the entities of the R. salicifolius aggregate that are recognized herein are kept separate pending additional taxonomic research.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Rumex lacustris is represented by two ecotypes: submerged aquatic forma lacustris (= forma aquatilis Rechinger f.), and terrestrial forma terrestris Rechinger f. The latter is unique among representatives of the R. salicifolius aggregate, which are normally glabrous, in having distinctly papillose-pubescent leaves. The species may occur also in the adjacent part of northern Nevada.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CA
