Jones: Flora of Illinois, 50. Polygon aceae 115 



1. RuMEX L. — Dock 



1. Leaver hastate, sometimes linear or lanceolate; plants with acid juice, dioe- 

 cious or polygamous; rhizomes horizontal. 



2. Calyx essentially unchanged in fruit; achenes granular, dull, much longer 

 than the sepals; fields, roadsides, waste ground, common; nat. from 

 Eur. May-July. Field Sorrel or Sour Dock R. acetorella L. 



2. Inner sepals winged in fruit, thin, reticulate, cordate, 3-4 mm. wide, en- 



closing the smooth, glossy achene; sandy soil; Madison Co., McDonald 



R. hastatulus Baldw. 



1. Leaves not hastate or markedly acid; flowers perfect; roots stout. 



3. Inner sepals (valves) entire or merely denticulate. 



4. Leaves flat, not crisped, pale green or glaucescent, acute at each end; 

 native species. 



5. Pedicels about equalling or shorter than the valves, curved. 



6. Only one valve (rarely two or three) bearing a tubercle; valves 

 4-5 mm. long; leaves lanceolate; roadsides and alluvial soil, 

 common. June. Pale Dock R. altissimus Wood 



6. Usually all three (rarely only 2) valves bearing a tubercle; valves 

 2.5-3 mm. long; leaves linear-lanceolate; sandy soil, not common. 



Chicago, Flick- June. [/?. viexicanus of auth., not Meisn.] 



R. triangulivahis (Danser) Rech.f. 



5. Pedicels several times longer than the valves, deflexed, nearly straight, 

 jointed close to the base; wet ground, common. June-July. Swamp 

 Dock R. verticillatus L. 



4. Leaves wavy-margined or crisped, dark green. 



7. Only one of the valves bearing a small or rudimentary tubercle; 

 valves cordate, nearly or quite entire, 5 6 mm. broad; pedicels 

 with a conspicuous joint; waste ground, occasional; nat from Eur. 

 May-July. Patience Dock R. patientia L. 



7. Usually all three valves bearing well-developed tubercles. 



8. Pedicels obscurely jointed; leaves 5-10 cm. wide, the lower ones 

 narrowed at the base; stem 1-2 m. tall; wet ground, not com- 

 mon; chiefly in the n. half of the state; Aug. -Sept. Water Dock 

 R. britannica L. 



8. Pedicels conspicuously jointed; leaves narrower, the lower ones 

 truncate or cordate at the base; stem 30-90 cm. tall; cult, and 

 waste ground, or roadsides, common; nat. from Eur. May-June. 

 Curly Dock R. crispus L. 



3. Valves with spinulose teeth. 



9. Valves 3-4 mm. long, deltoid, reticulate, only one tubercled; pedicels 

 jointed below the middle; lowest leaves broadly ovate, cordate at the 

 base; plants perennial; fields and roadsides, common; nat. from Eur. 

 July-Aug. Bitter Dock R. obtusifolius L. 



9. Valves 2 mm. long, with slender teeth, all three valves tubercled; pedi- 



