POLYGONACEAE 113 



2. ARISTOLOCHIA h- 



Low herb : calyx about i cm. broad : capsules globular, about i cm. in diam- 

 eter. I. A. Serpentaria. 



Tall twining vine ; calyx about 2 cm. broad : capsules oblong-cylindric, 5-7 5 

 cm. long. ^. A. macrophylla. 



1. Aristolochia Serpentaria L. Virginia SnakerooT. (Man. p. 

 349 ; I. F. /. 1281.) In dry woods, Conn, to Mich., Fla., La. and Mo. — 

 Pennsylvania : Northampton ; Dei<aware ; Berks ; Franklin ; 

 Huntingdon ; Westmoreland ; Armstrong ; Lancaster ; Somer- 

 set ; Chester ; Allegheny. 



2. Aristolochia macrophylla Lam. Dutchman's Pipe. (Man. p. 

 350; I. F. /. 1283.) In rich woods, Pa. to Minn., Ga. and 'Kans.— Pe7in- 

 sylvania : GREENE ; ALLEGHENY. 



Order 9. POLYGONALES. 

 Family i. POLYGONACEAE Lindl. Buckwheat Family. 

 Stigmas tufted. i. Rumex. 



Stigmas minute, capitate. 

 Seed with an embryo dividing the endo-'iperm by an S-shapcd curve. 



2. Fagopyrum. 

 Seed with an embryo curved along one angle of the endosperm. 



.3. POLYGONBM. 

 1. RUMEX L. 



Leaf-blades hastate : flowers dioecious : plants acid. 

 Inner sepals not developing wings : achene granular. i. R. Aceiosella. 

 Inner sepals developing wings at maturity : achene smooth. 



2., R. Acetosa. 

 Leaf -blades not hastate : flowers perfect or polygamo-dioecious : plants scarcely 

 or not at all acid. 

 Leaves with flat blades, manifestly bright or light green, or glaucescent. 

 All 3 sepal-wings usually bearing tubercles. 3. R. verlicillatus. 



Only I sepal-wing usually bearing a tubercle. 4. R. altissimus. 



Leaves with crisped blades, manifestly dark or deep green, not glaucescent. 

 Sepal-wings entire, more or less undulate. 

 Lower leaf-blades narrowed or acuminate at the base. 

 Only I sepal-wing bearing a tubercle. 5. R. Patientia. 



All 3 sepal-wings bearing a tubercle. 6. R. Brilannica. 



Lower leaf-blades rounded or cordate at the base. 

 All 3 sepal-wings usually bearing tubercles. 7. R. crispus. 



Only I sepal-wing bearing a tubercle. 8. R. sanguineus. 



Sepal-wings fringed with spiny teeth. 9. R. obHisif alius . 



1. Rumex Acetosella L. Field or Sheep Sorrel. (Man. p. 354 ; 

 I. F. f. 1299.) In dry fields and on hillsides throughout N. Am. except 

 the extreme north. Chiefly nat. from Ku.— Pennsylvania : NorThamp- 



■ TON ; Bucks ; Lancaster ; Franklin ; Columbia ; Huntingdon ; 

 Monroe ; Tioga ; Chester ; Delaware ; Allegheny. 



2. Rumex Acetosa L. Sorrel. Sour Dock. (Man. p. 355 ; I. F. 

 f. 1301.) In sandy or stony soil, Labrador to Alaska. Nat. from Eu. 

 in Vt., N. Y. and Pa. — Pennsylvania : Tioga, Brookfield. 



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