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 | R. 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 | R. 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 | R. 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 | R. krausei |
6. Leaf blades cuneate at base, usually not hastate or sagittate; Rocky Mountains region | R. 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 | R. 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 | R. 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 | R. 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 | R. 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. | R. 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) | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. ellipticus |
18. Inner tepals broadly triangular, ovate-triangular, or broadly ovate-deltoid,tubercles (2-)3; stems normally erect, rarely ascending | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. pallidus |
26. Leaf blades thin (rarely subcoriaceous), often with undulate margins; inner tepals ovate to ovate-lanceolate; tubercles 3, unequal (1 distinctly larger), smooth | R. 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 | R. 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 | R. 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 | R. 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 | R. mexicanus |
30. Inner tepals (2-)2.5-3.5(-3.8) mm; achenes 1.7-2.2 mm | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. 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) | R. 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 | R. densiflorus |
39. Inner tepals gradually narrowed into acute apex, widest in proximal 1/ 3; leaf blades with lateral veins ± equal in size | R. 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) | R. 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 | R. 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 | R. 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 38. Rumex occidentalis [31. Shifted to left margin.—Ed.] | → 31 |
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 | R. 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 | R. 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 | R. 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 | R. 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) | R. 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) | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. crispus |
55. Inner tepals triangular, with 3-5 distinctly hooked teeth on each side, apex hooked, tubercles absent, or midveins indistinctly swollen | R. 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 | R. 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 | R. 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 | R. 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 | R. 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 | R. 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) | R. 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 | R. 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) | R. obovatus |
64. Inner tepals 3-4 mm; tubercles smooth or minutely punctate, apex acute or subacute | R. 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) | R. 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 | R. dentatus |