Show Lower Taxa
Rumex
Sp. Pl. 1: 333. 1753.
Gen. Pl. ed. 5, 156. 1754.
Common names: Dock sorrel
Etymology: classical Latin name for sorrel, probably derived from rumo, to suck, alluding to the practice among Romans of sucking the leaves to allay thirst
Treatment appears in FNA Volume 5. Treatment on page 489. Mentioned on page 216, 218, 479, 480, 490, 523, 532.
Herbs, perennial, biennial, or annual, synoecious (subg. Rumex and Platypodium) or dioecious (subg. Acetosa and Acetosella), occasionally polygamomonoecious, with taproots and usually short caudex, or sometimes rhizomatous and/or stoloniferous. Stems erect, ascending, or prostrate, glabrous or papillose-pubescent. Leaves basal (in some species) and cauline, alternate, petiolate; ocrea persistent or partially deciduous, membranous; petioles present on basal and proximal cauline leaves, absent on distal cauline leaves, bases not articulated; blades variable in shape, basal (if present) and proximal cauline leaves from broadly ovate or almost orbiculate to linear, becoming progressively smaller and narrower distally, margins entire (or basally lobate), flat, or occasionally undulate or crisped. Inflorescences terminal, sometimes terminal and axillary, paniclelike, rarely simple. Pedicels present. Flowers bisexual or unisexual, (1–)4–30 per ocreate fascicle, base stipelike; perianth green, pinkish, or red, campanulate, glabrous; tepals (5–)6, connate proximally, sepaloid, dimorphic, outer 3 remaining small, inner 3 usually enlarging, sometimes 1–3 with central vein transformed into tuberculate callosity (tubercle); stamens 6; filaments distinct, free, glabrous; anthers, yellow to brownish yellow, ovate to elongate; styles 3, spreading or reflexed, distinct; stigmas 3, fimbriate or plumose. Achenes included in accrescent and usually veiny perianth, tan to dark brown, unwinged to weakly winged, 3-gonous, sometimes compressed-3-gonous or nearly pyramidal, glabrous. Seeds: embryo straight. x = 7, 8, 9, 10 (polyploidy widespread in the genus).
Distribution
Almost worldwide, but mostly in temperate regions of both hemispheres, some taxa occur in many regions of the world as naturalized or casual aliens.
Discussion
Species 190–200 (63 in the flora).
Carefully collected mature specimens with well-developed inner tepals are desirable for reliable identification of Rumex species. Vegetative characters (in particular, growth habit, basal and proximal cauline leaves, and inflorescences) also are crucial.
In Rumex the distal part of a functional pedicel (below the articulation with a true pedicel) is formed by the narrowed connate basal parts of the outer tepals (also known as a stipelike hypanthium base or pseudopedicel). However, for simplification of the keys and descriptions, the whole functional pedicel (including pseudopedicel) is referred to simply as pedicel.
The genus Rumex in the broad sense may be divided into at least four segregate genera: Rumex in the narrow sense, Acetosa, Acetosella, and Bucephalophora (see e.g., Á. Löve 1983; Löve and B. M. Kapoor 1967; N. N. Tzvelev 1987b, 1989b). These taxa probably represent distinct phylogenetic lineages; they have, however, not been generally accepted as separate genera by most taxonomists, including K. H. Rechinger (1937, 1949), monographer of Rumex in the broad sense. Moreover, in some cases they are connected by intermediate forms (especially Acetosa and Acetosella) and evidently are more closely related to each other than to any outgroup genus. In my opinion, this favors the retention of Rumex in the traditional broad sense, which is also nomenclaturally convenient.
Many Old World species of Rumex may be divided in their native areas of distribution into quite distinct subspecies or varieties. However, the same species occurring in North America as introduced aliens often are represented by atypical, intermediate specimens or even populations (as is true also for many native North American taxa occurring as aliens in Europe), which in many cases obscures those taxonomic distinctions.
Rumex rugosus Campderá, a commonly cultivated European species, was reported for North America by Á. Löve and D. Löve (1957) as a cultivated and occasionally escaped garden plant “in a few places in eastern Canada.” No specimens from escaped plants in the flora area have been seen.
Selected References
Key
| 1 | Plants dioecious (rarely polygamomonoecious); flowers mostly unisexual; leaf blades in most species hastate or sagittate, with usually acute basal lobes (sometimes leaves not lobed, cuneate or narrowly cuneate at base, then pedicel articulated near base of tepals); pedicels in most cases with evident articulation | > 2 |
| 1 | Plants synoecious (rarely polygamodioecious or dioecious individuals in some species); flowers normally bisexual, sometimes bisexual and unisexual within same inflorescence; leaf blades never hastate or sagittate; pedicels with or without evident articulation [25c. Rumex subg. Rumex and 25d. subg. Platypodium] | > 10 |
| 2 | Pedicels articulated near base of tepals; outer tepals normally angled towards inner tepals; inner tepals not enlarged or slightly enlarged, normally 1.2-2.5(-3) mm, equaling to slightly wider than achenes; tubercles absent; leaf blades hastate at base, or in some species cuneate [25a. Rumex subg. Acetosella] | > 3 |
| 2 | Pedicels with articulation near middle, or in proximal part; outer tepals normally reflexed towards pedicel, or sometimes spreading; inner tepals distinctly enlarged, normally 2.5-5 mm (rarely more), always distinctly wider and longer than achene; tubercles small, recurved, developed only at base of inner tepals, occasionally absent; leaf blades in most species sagittate at base, sometimes hastate (normally in R. hastatulus, and occasionally in R. thyrsiflorus), cuneate (in R. paucifolius), or almost cordate (in R. rugosus) [25b. Rumex subgen. Acetosa] | > 6 |
| 3 | At least basal leaf blades obovate-oblong, ovate-lanceolate, lanceolate-elliptic, or lanceolate (rarely linear-lanceolate), base hastate or at least broadly cuneate (almost truncate); inner tepals not enlarged, or rarely slightly enlarged at maturity, free wing absent to barely visible; widespread | Rumex acetosella |
| 3 | Leaf blades narrowly linear, linear-oblanceolate, or distinctly spatulate, base usually not hastate (rarely some leaf blades with indistinct basal lobes), narrowly cuneate; inner tepals usually distinctly enlarged, free wing 0.2-0.6(-1) mm wide; arctic and subarctic | > 4 |
| 4 | Plants with elongated underground stolons; inflorescences usually lax, with branches often reflexed; shoots not crowded, ± elongated, covered with whitish or silvery membranous ocreae at base | Rumex graminifolius |
| 4 | Plants with thick, densely tufted underground stolons; inflorescences ± dense, with branches directed upward; shoots usually densely crowded, not elongated, covered with brownish or reddish brown membranous ocreae at base | > 5 |
| 5 | Inflorescences interrupted at least at base, branched, occupying more than distal 1/ 2 of stem; inner tepals 1.6-2.3 × 1.8-2.5 mm (free wing 0.3- 0.5 mm wide); achenes 1-1.5 mm | Rumex beringensis |
| 5 | Inflorescences dense, simple or with few short branches, occupying distal 1/ 2 of stem; inner tepals 2.3-3 × 1.8-3 mm (free wing 0.4-0.8 mm wide);achenes 1.5-2 mm | Rumex krausei |
| 6 | Leaf blades cuneate at base, usually not hastate or sagittate; Rocky Mountains region | Rumex paucifolius |
| 6 | Leaf blades normally hastate or sagittate at base (rarely cuneate in underdeveloped plants); various regions (if in Rocky Mountains, then leaf blades sagittate at base) | > 7 |
| 7 | Leaf blades distinctly hastate at base, with spreading lobes (occasionally cuneate); inner tepals 2.7-3.2 mm wide; plants mostly annual or short-lived perennial | Rumex hastatulus |
| 7 | Leaf blades sagittate at base, with lobes directed downward (towards petiole), sometimes also slightly incurved inward, or reflexed outward; inner tepals in (2.5-)3-4.5 mm wide; plants perennial | > 8 |
| 8 | Rootstock thick, vertical or oblique (reaching deep into substrate), with remote 2d-order roots; 1st-order branches of inflorescence usually repeatedly branched, with numerous 2d-order branches; inflorescences broadly paniculate (in R. lapponicus occasionally simple), pyramidal,usually dense | Rumex thyrsiflorus |
| 8 | Rootstock rather thin, horizontal or slightly oblique, short (not reaching deep into substrate), or plants rhizomatous; 1st-order branches of inflorescence usually simple or with few 2d-order branches; inflorescences narrowly paniculate, cylindric, usually lax | > 9 |
| 9 | Ocreae entire (or sometimes laciniate only in distal parts); achenes dark brown to brownish yellow, usually dull; leaf blades broadly ovate (rarely almost rounded), oblong-ovate, or rarely oblong-lanceolate, normally less than 2.5 times as long as wide | Rumex lapponicus |
| 9 | Ocreae laciniate (especially in middle and upper cauline leaves); achenes black to dark brown, shiny, smooth; leaf blades oblong-ovate to lanceolate, normally more than 2.5 times as long as wide | Rumex acetosa |
| 10 | Plants not developing basal rosette of leaves; stems erect, ascending, procumbent, or decumbent, normally with regular, leafy axillary shoots tending to develop 2d-order axillary inflorescences (often overtopping 1st-order ones); leaf blades mostly lanceolate, elliptic, ovate, ovate-lanceolate, or ovate-elliptic, base cuneate or almost rounded, or in some species broadly cuneate; inner tepal margins entire (rarely in some species minutely erose-denticulate) [25c.1. Rumex sect. Axillares] | > 11 |
| 10 | Plants developing basal rosette of leaves (sometimes, especially in annual species, not persistent at maturity); stems mostly erect, sometimes ascending, spreading, or almost prostrate, simple or several from base, not branching below terminal paniculate inflorescence (single racemose in R. bucephalophorus), without axillary shoots; leaf blades variable in shape, base cordate to cuneate (rarely rounded in R. bucephalophorus); inner tepal margins entire or variously dentate [25c.2. Rumex sect. Rumex] | > 31 |
| 11 | Inner tepals (20-)23-30 mm wide. | Rumex venosus |
| 11 | Inner tepals normally less than 15 mm wide | > 12 |
| 12 | Pedicels 2.5-5 times as long as inner tepals, articulated in proximal part | > 13 |
| 12 | Pedicels usually not more than 2-2.5 times as long as inner tepals, articulated near middle or in proximal 2 | > 15 |
| 13 | Leaf blades ovate or ovate-elliptic, ca. 2 times as long as wide, lateral veins forming angle of 80° with midvein (especially near base) | Rumex fascicularis |
| 13 | Leaf blades linear-lanceolate, narrowly to broadly lanceolate (rarely ovate-lanceolate in R. floridanus), at least 3 times as long as wide, lateral veins forming angle of 4-60° with midvein | > 14 |
| 14 | Leaf blades mostly linear-lanceolate, 5-7(-10) times as long as wide, thin; inflorescences normally interrupted (at least in basal 2); pedicels ca. 3-5 times as long as inner tepals; inner tepals longer than wide, or rarely as long as wide | Rumex verticillatus |
| 14 | Leaf blades mostly lanceolate to broadly lanceolate, 3-5(-6) times as long as wide, coriaceous and somewhat fleshy; inflorescences normally rather dense (sometimes interrupted only at base); pedicels ca. 2.5-3 times as long as inner tepals; inner tepals as wide as or wider than long | Rumex floridanus |
| 15 | Leaf blades distinctly obovate or obovate-elliptic, widest in distal 1/ 2, coriaceous, apex obtuse, rounded; plants with long-creeping underground rhizomes and/or stolons, producing ascending or erect axillary shoots (5-)10-30(-40) cm | Rumex cuneifolius |
| 15 | Leaf blades ovate-lanceolate, elliptic-lanceolate, lanceolate, or linear-lanceolate, widest near middle or in proximal 1/ 2, subcoriaceous or coriaceous, apex acute (sometimes subobtuse, but never rounded); plants usually with vertical rootstock, occasionally with creeping rhizomes | > 16 |
| 16 | Inner tepals broadly cordate or broadly ovate-deltoid, 7-10 × 8-12 mm; leaf bladesrounded or broadly truncate at base | Rumex spiralis |
| 16 | Inner tepals ovate, triangular, or deltoid, always less than 7 mm × 1-5 mm; leaf blades in most cases cuneate at base, rarely subtruncate | > 17 |
| 17 | Leaf blades ovate-lanceolate or elliptic-lanceolate, distinctly widest in proximal 1/2; inner tepals usually (4.5-)5-6 mm | > 18 |
| 17 | Leaf blades in most cases lanceolate or linear-lanceolate, usually widest near middle; inner tepals usually 1.7-7 mm (in some species leaf blades ovate-elliptic or elliptic-lanceolate, but then inner tepals always less than 5 mm) | > 19 |
| 18 | Inner tepals ovate or cordate-triangular (occasionally almost orbiculate), tubercles absent; stems normally ascending to decumbent | Rumex ellipticus |
| 18 | Inner tepals broadly triangular, ovate-triangular, or broadly ovate-deltoid,tubercles (2-)3; stems normally erect, rarely ascending | Rumex altissimus |
| 19 | Inner tepals without tubercles (rarely 1 inner tepal with somewhat thickened midvein) | > 20 |
| 19 | At least 1 inner tepal with distinct tubercle, or all inner tepals with tubercles | > 22 |
| 20 | Inner tepals with margins minutely but distinctly denticulate, rarely subentire; inflorescences lax and broadly paniculate; stems ascending to suberect | Rumex californicus |
| 20 | Inner tepals with margins entire, sometimes margins indistinctly crenulate, but then inflorescences dense and paniculate or/and stems prostrate | > 21 |
| 21 | Inner tepals 2.5-3 × 2.5-3 mm; inflorescences dense, broadly paniculate, with crowded branches; leaf blade margins normally flat (sometimes slightly undulate); stems erect or ascending | Rumex utahensis |
| 21 | Inner tepals 3-4 × 3.2-4(-4.5) mm; inflorescences rather dense toward apex, usually broadly paniculate, interrupted in proximal 1/ 2, with remote branches almost perpendicular to main axis; leaf blade margins strongly undulate or crenulate; stems usually procumbent | Rumex subarcticus |
| 22 | All or at least 1 tubercle large, subequal to inner tepals, or slightly narrower than inner tepals (then free margins of inner tepals distinctly narrower than tubercle) | > 23 |
| 22 | Tubercles much narrower than inner tepals (free margins of inner tepal wider than or at least as wide as tubercle) | > 27 |
| 23 | Leaf blades thick, coriaceous, ovate-lanceolate, elliptic-lanceolate, or ovate-elliptic, not more than 2-3.5 times as long as wide; inner tepals (3-)4-5 × (2.5-)3-4 mm; tubercle 1 | Rumex crassus |
| 23 | Leaf blades thin, or in some species thick, occasionally coriaceous or subcoriaceous, oblanceolate, lanceolate, or linear-lanceolate, usually more than (3-)3.5 times as long as wide; inner tepals (1.7-)2-4 × (1.5-)1.8-3(-3.5) mm; tubercles 1-3 | > 24 |
| 24 | Inner tepals (1.8-)2-2.5(-3) mm; tubercle 1 | Rumex salicifolius |
| 24 | Inner tepals 2.5-4 mm; tubercles 3 (sometimes 1 or 2 distinctly smaller) | > 25 |
| 25 | Inner tepals usually 2.5-3(-3.5) mm, distinctly longer than tubercles | Rumex sibiricus |
| 25 | Inner tepals usually 3-4 mm, subequal to or slightly longer than tubercles | > 26 |
| 26 | Leaf blades rather thick, coriaceous, margins flat or slightly undulate; inner tepals deltoid-ovate; tubercles 3, equal, often minutely verrucose | Rumex pallidus |
| 26 | Leaf blades thin (rarely subcoriaceous), often with undulate margins; inner tepals ovate to ovate-lanceolate; tubercles 3, unequal (1 distinctly larger), smooth | Rumex transitorius |
| 27 | Inner tepals 2-2.5(-3) mm, ovate or elliptic; leaf blades of aquatic submerged forms usually ovate-lanceolate to lanceolate, glabrous or nearly so; those of terrestrial forms lanceolate, papillose-pubescent abaxially | Rumex lacustris |
| 27 | Inner tepals normally more than (2.5-)3 mm, elliptic-lanceolate to linear-lanceolate; leaf blades of terrestrial or riparian plants linear-lanceolate, lanceolate; or elliptic-lanceolate, glabrous or nearly so | > 28 |
| 28 | Inflorescences lax, distinctly interrupted; leaf blades thick, coriaceous, deep olive green, with strongly prominent veins abaxially, apex subobtuse; inner tepals orbiculate to ovate-triangular | Rumex chrysocarpus |
| 28 | Inflorescences rather dense, not interrupted, or interrupted only in proximal part; leaf blades thin, not coriaceous, light green to yellowish green, with scarcely prominent veins abaxially, apex in most cases distinctly acute; inner tepals triangular | > 29 |
| 29 | Leaf blades elliptic-lanceolate or lanceolate, ca. (2-)3(-5) times as long as wide; tubercle 1 | Rumex hesperius |
| 29 | Leaf blades narrowly lanceolate or linear-lanceolate, normally more than 5 times as long as wide; tubercles 3 (1 in some forms of R. triangulivalvis) | > 30 |
| 30 | Inner tepals 3.5-4.5(-5) mm; achenes 2-3 mm | Rumex mexicanus |
| 30 | Inner tepals (2-)2.5-3.5(-3.8) mm; achenes 1.7-2.2 mm | Rumex triangulivalvis |
| 31 | Inner tepals with tubercles absent (or sometimes 1 inner tepal with indistinct tubercle or slightly thickened midvein in R. longifolius and R. pseudonatronatus), margins entire, indistinctly erose or, rarely, minutely denticulate | > 32 |
| 31 | Inner tepals with at least 1 distinct tubercle, margins entire, denticulate, or variously dentate (sometimes tubercle absent, or inner tepals with indistinctly swollen midvein, then margins prominently dentate, with hooked teeth) | > 43 |
| 32 | Inner tepals 11-16 mm; ocreae prominent; roots distinctly tuberous | Rumex hymenosepalus |
| 32 | Inner tepals usually less than 10 mm; ocreae less prominent; roots not tuberous. [33. Shifted to left margin.—Ed.] | > 33 |
| 33 | Pedicels with distinctly swollen articulation point | > 34 |
| 33 | Pedicels without swollen articulation point | > 36 |
| 34 | Plants with creeping rootstock; leaf blades to broadly orbiculate to ovate-orbiculate, base deeply cordate; inner tepals ovate to ovate-triangular | Rumex alpinus |
| 34 | Plants with vertical rootstock; leaf blades oblong, lanceolate, or narrowly lanceolate, base cuneate, truncate, or occasionally indistinctly cordate; inner tepals orbiculate, reniform, or cordate-orbiculate | > 35 |
| 35 | Leaf blades 15-30 × 1-4 cm, base narrowly cuneate; inner tepals 3- 5 mm wide;achenes usually reddish brown, less than 1-1.5 mm wide | Rumex pseudonatronatus |
| 35 | Leaf blades 25-50(-60) × 7-15 cm, base broadly cuneate, rounded-truncate, or slightly cordate; inner tepals (4.5-)5-7(-7.5) mm wide; achenes dark brown or brown, normally 1.5-2 mm wide | Rumex longifolius |
| 36 | Plants with creeping rootstock or rhizome; inner tepals with margins entire to minutely dentate (especially near base) [Rumex densiflorus group] | > 37 |
| 36 | Plants with vertical rootstock (or sometimes with short oblique rootstock); inner tepals with margins entire or rarely weakly erose [Rumex aquaticus group] | > 40 |
| 37 | Leaf blades elliptic or oblong, sometimes almost orbiculate, ca. 2(-2.5) times as long as wide, apex obtuse or subacute; base rounded or broadly cuneate; inflorescences occupying more than proximal 2 of stem | Rumex praecox |
| 37 | Leaf blades usually oblong-lanceolate, sometimes oblong, usually more than 3 times as long as wide, apex acute or subacute rarely obtuse, base weakly cordate, truncate, or broadly cuneate; inflorescences occupying distal 1/ 2 of stem | > 38 |
| 38 | Inner tepals ovate-triangular or ovate-deltoid, widest at base, apex narrowly acute, margins usually minutely erose or weakly serrate (at least near base) | Rumex pycnanthus |
| 38 | Inner tepals ovate-deltoid, ovate-triangular, or subcordate, widest above base, apex acute to subacute, margins entire to indistinctly erose, rarely minutely denticulate near base | > 39 |
| 39 | Inner tepals abruptly contracted at apex, widest near middle; leaf blades with large lateral veins alternating with short ones | Rumex densiflorus |
| 39 | Inner tepals gradually narrowed into acute apex, widest in proximal 1/ 3; leaf blades with lateral veins ± equal in size | Rumex orthoneurus |
| 40 | Plants densely tomentose and/or papillose-pubescent (especially abaxial sides of leaf blades, ocreae, and petioles); pedicel distinctly swollen at distal part (near base of tepals, not at articulation point) | Rumex tomentellus |
| 40 | Plants glabrous or nearly so (rarely sparsely papillose-pubescent); pedicel not distinctly swollen | > 41 |
| 41 | Pedicel 12-20 mm, 3(-4) times as long as inner tepals | Rumex nematopodus |
| 41 | Pedicel 5-13(-17) mm, usually not more than 2-2.5 times as long as inner tepals | > 42 |
| 42 | Leaf blades narrowly lanceolate, lanceolate, or oblong-lanceolate, base cuneate to broadly cuneate; inflorescences usually simple or with comparatively short branches less than 7-8 cm | Rumex arcticus |
| 42 | Leaf blades ovate-triangular, ovate-lanceolate, or oblong-lanceolate, base distinctly to weakly cordate, occasionally rounded or truncate; inflorescences normally with comparatively long branches more than 7-8 cm | Rumex occidentalis |
| 43 | Inner tepals with margins entire or minutely and indistinctly erose-denticulate (teeth less than 0.2 mm); however, in 3 species (R. stenophyllus, R. cristatus, R. kerneri) often more distinctly dentate, then inner tepals reniform, orbiculate, broadly ovate, or broadly ovate-triangular (ca. as long as wide, or wider than long), base often cordate | > 44 |
| 43 | Inner tepal margins variously dentate (at least some teeth 0.3 mm or longer, almost always evidently longer than wide (excluding teeth), base variable but normally not cordate | > 55 |
| 44 | Inner tepals oblong-lanceolate, oblong, lingulate, ca. 2 times as long as wide, margins entire, largest tubercle almost as wide as inner tepal | > 45 |
| 44 | Inner tepals orbiculate, broadly ovate, or broadly ovate-triangular (deltoid or triangular-deltoid only in R. violascens), ca. as long as wide (or at least always distinctly less than 2 times as long as wide), margins entire or denticulate, largest tubercles normally much narrow than inner tepals | > 46 |
| 45 | Tubercles 3, equal or subequal; inflorescences with almost all but distalmost flower whorls with subtending leaves (panicle leafy at least in proximal 2/ 3 of length), dense; pedicels 1-4(-5) mm | Rumex conglomeratus |
| 45 | Tubercle 1 (occasionally 3, then 1 much larger); inflorescences with only proximalmost flower whorls with subtending leaves (panicle leafless, or leafy only near base), lax; pedicels (2-)4-6(-8) mm | Rumex sanguineus |
| 46 | Plants annual or biennial, sometimes short-lived perennials, native to sw United States and Mexico; inner tepals deltoid or triangular-deltoid, ca. 1.5 times as long as wide; branches of inflorescences usually distinctly flexuous | Rumex violascens |
| 46 | Plants perennial, mostly introduced; inner tepals orbiculate to broadly ovate-triangular, in most species as long as wide or nearly so; branches of inflorescences usually straight or arcuate, rarely indistinctly flexuous | > 47 |
| 47 | Inner tepal margins denticulate or dentate, at least proximally | > 48 |
| 47 | Inner tepal margins entire or subentire to or weakly erose | > 50 |
| 48 | Inner tepals normally less than 6 mm, with 3 equal or subequal tubercles | Rumex stenophyllus |
| 48 | Inner tepals normally more than 6 mm, with 1 distinct tubercle, other inner tepals without tubercles or tubercles small | > 49 |
| 49 | Inner tepals usually with 1 tubercle, teeth to 0.5 mm; branches of inflorescences mostly simple or nearly so; leaf blades distinctlypapillose abaxially (on veins) | Rumex kerneri |
| 49 | Inner tepals usually with 3 unequal tubercles, teeth 0.5-1 mm; branches of inflorescences mostly with 2d-order branches; leaf blades indistinctly papillose to glabrous abaxially (on veins) | Rumex cristatus |
| 50 | Inner tepals with 1 indistinct tubercle less than 1(-1.3) mm, or some with tubercles absent (usually both types occur within same inflorescence) | > 51 |
| 50 | Inner tepals normally with 3 tubercles, or at least with 1 distinct tubercle more than (1-)1.5 mm wide | > 52 |
| 51 | Leaf blades 15-30 × 1-4 cm, base narrowly cuneate; inner tepals usually 3-5 mm wide; achenes reddish brown, usually 1-1.5 mmwide | Rumex pseudonatronatus |
| 51 | Leaf blades 25-50(-60) × 7-15 cm, base broadly cuneate; inner tepals (4.5-)5-7(-7.5) mm wide; achenes brown to dark brown, normally 1.5-2 mm wide | Rumex longifolius |
| 52 | Inner tepals with 3 distinctly equal or subequal tubercles; leaf blades 20-55(-70) cm, lanceolate or oblong-lanceolate, base cuneate, occasionally or rounded or truncate | Rumex britannica |
| 52 | Inner tepals with 1 tubercle, or with 3 unequal tubercles, at least 1 tubercle distinctly larger; leaf blades variable (rarely tubercles subequal, then largest leaves smaller than 55 cm) | > 53 |
| 53 | Leaf blades broadly ovate, ovate-triangular, or ovate-elliptic, base deeply and broadly cordate, apex obtuse to subacute; tubercle usually 1 | Rumex confertus |
| 53 | Leaf blades ovate-lanceolate, oblong-lanceolate, or lanceolate, base cuneate, truncate, or subcordate, apex acute or subacute; tubercles 1-3 | > 54 |
| 54 | Leaf blades ovate-lanceolate or oblong-lanceolate, margins flat or weakly undulate; inner tepals (5-)5.5-8(-10) mm, broadly ovate to orbiculate, base usually distinctly cordate; tubercles normally 1 (occasionally 2-3); stems usually 80-150(-200) cm | Rumex patientia |
| 54 | Leaf blades usually lanceolate, margins strongly undulate and crisped; inner tepals 3.5-6 mm, orbiculate-ovate or ovate-deltoid, base truncate, or subcordate; tubercles normally 3 (rarely 1-2); stems 40-100(-150) cm | Rumex crispus |
| 55 | Inner tepals triangular, with 3-5 distinctly hooked teeth on each side, apex hooked, tubercles absent, or midveins indistinctly swollen | Rumex brownii |
| 55 | Inner tepals various in shape, with straight apex and teeth (only in R. bucephalophorus sometimes with hooked, slender lateral teeth, but without hook at apex); at least 1 inner tepal with tubercle or (in R. bucephalophorus) tubercles absent | > 56 |
| 56 | Plants annual (rarely biennial); leaf blades lanceolate or spatulate; flowers 2-3(-4) in whorls; pedicels usually distinctly heteromorphic, some swollen, curved, or clavate, others not swollen | Rumex bucephalophorus |
| 56 | Plants perennial, annual, or biennial; leaf blade variable; flowers normally more than 3-4 in whorls; pedicels homomorphic | > 57 |
| 57 | Leaf blades lanceolate-linear or lanceolate (rarely oblong-lanceolate), at least 4 times as long as wide; inner tepal margins with long bristlelike or subulate-filiform teeth longer than or equaling width of inner tepals (very rarely teeth shorter, or even absent); inner tepals (excluding teeth) narrowly triangular or narrowly rhombic-triangular, normally ca. 2 times as long as wide; plants annual (less commonly biennial or short-lived perennial) | > 58 |
| 57 | Leaf blades ovate, obovate to elongate, occasionally broadly oblong-lanceolate, less than 4 times as long as wide; inner tepal margins with short-subulate or triangular-subulate (not bristlelike) teeth equaling or shorter than width of inner tepals (occasionally longer in some forms of R. dentatus and R. pulcher); inner tepals (excluding teeth) usually deltoid or broadly triangular (occasionally ligulate) normally ca. 1.5 times as long as wide (occasionally ca. 2 times as long as wide in some forms of perennial R. obtusifolius); plants annual, biennial, or perennial | > 61 |
| 58 | Leaf blades narrowly cuneate (rarely broadly cuneate) at base; inflorescence branches and leaf blades glabrous or indistinctly papillose; tubercles in most cases smooth (occasionally finely striate or indistinctly pitted in herbarium specimens); uncommon introduced species | > 59 |
| 58 | Leaf blades slightly cordate, abruptly truncate, or broadly cuneate at base; inflorescence branches and leaf blades usually distinctly papillose-pubescent abaxially; tubercles usually distinctly reticulate-pitted; native species | > 60 |
| 59 | Inner tepals (2.5-)3-3.5(-4) mm, teeth (bristles) ca. as long as width of inner tepals, tubercles obtuse at apex; inflorescences normally reddish brown, with flower whorls distinctly interrupted in proximal 1/ 2/ 3 | Rumex palustris |
| 59 | Inner tepals 2.5-3(-3.5) mm, teeth (bristles) usually 1.5-2 times as long as width of inner tepals, tubercles acute or subacute at apex; inflorescences normally golden or greenish yellow, with flower whorls usually rather dense or interrupted in proximal part | Rumex maritimus |
| 60 | Tubercles straw-colored, oblong-ovate, apex obtuse, almost as wide as inner tepals; inner tepal margins with teeth (bristles) ± equal to width of inner tepals | Rumex persicarioides |
| 60 | Tubercles brownish or reddish, linear-lanceolate to fusiform, apex normally acute to subacute, distinctly narrower than inner tepals (ca. 0.5 times width of inner tepals); inner tepal margins with teeth (bristles) variable, but normally 1.5-2.5(-4) times as long as width of inner tepals | Rumex fueginus |
| 61 | Plants perennial; leaf blades oblong to ovate-oblong, sometimes panduriform in R. pulcher, base usually distinctly cordate (rarely truncate or rounded) | > 62 |
| 61 | Plants annual or biennial (rarely short-lived perennial); leaf blades variable, base cuneate, truncate, or subcordate | > 63 |
| 62 | Stems 20-60(-70) cm; leaf blades 4-10(-15) cm; inflorescence branches divaricately spreading (forming angle of 60-90° with 1st-order stem); tubercles usually verrucose (warty) | Rumex pulcher |
| 62 | Stems 60-120(-150) cm; leaf blades 20-40 cm; inflorescence branches less spreading (normally forming angle of 30-45° with 1st-order stem); tubercles smooth | Rumex obtusifolius |
| 63 | Leaf blades distinctly obovate (rarely panduriform), usually coriaceous, apex obtuse, base cuneate (rarely rounded) | > 64 |
| 63 | Leaf blades elongate, ovate, oblong-lanceolate, obovate-elliptic, normally not coriaceous (occasionally subcoriaceous in R. violascens), apex obtuse or subacute, base subcordate, rounded, truncate, or broadly cuneate | > 65 |
| 64 | Inner tepals 4-5(-5.5) mm; tubercles distinctly verrucose (warty), apex obtuse (rarely subacute) | Rumex obovatus |
| 64 | Inner tepals 3-4 mm; tubercles smooth or minutely punctate, apex acute or subacute | Rumex paraguayensis |
| 65 | Plants annual or biennial (occasionally short-lived perennial); leaf blades oblong-lanceolate to obovate-elliptic, base broadly cuneate to rounded; inner tepal margins with longest tooth less than 0.5 mm (rarely some inner tepal margins subentire) | Rumex violascens |
| 65 | Plants annual (rarely biennial); leaf blades oblong, elliptic-lanceolate, or ovate-elliptic, base truncate or subcordate to weakly cordate; inner tepal margins with teeth 1-3(-5) mm | Rumex dentatus |