POIvYGONACEAE 113 



2. ARISTOLOCHIA L. 



I^ow herb : calyx about i cm. broad : capsules globular, about i cm. in diam- 

 eter. I. A. Serpenlaria. 



Tall twining vine : calyx about 2 cm. broad : capsules oblong-cylindric, 5-7.5 

 cm. long. 2. A. macrophylla. 



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

 349; I. F. y. 1281.) In dry woods, Conu. to Mich., Fla., La. aud Mo. — 

 Pennsylvania: Northampton; Dei.aw.-\re ; Berks; Franklin; 

 Huntingdon ; Westmoreland ; Armstrong ; Lancaster ; Somer- 

 set ; Chestkr ; Allegheny. 



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

 350; I. F. y. 12SJ.) In rich woods. Pa. to Minn., Ga. and Kans. — Penn- 

 sylvania : Greene ; Allegheny. 



Order 9. POLYGONALES. 

 Famii^y i. POLYGONACEAE Lindl. Buckwheat Famii^y. 

 vStigmas tufted. i. Rumex. 



Stigmas minute, capitate. 

 Seed with an embryo dividing the endosperm by an S-shapcd curve. 



2. Fagopyrum. 

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



3. Polygonum. 

 1. RUMEX L. 



Leaf-blades hastate : flowers dioecious : plants acid. 

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

 Inner sepals developing wings at maturity : achene smooth. 



2. R. Acelosa. 

 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. verticillatus. 



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



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. Fatientia. 



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. savguineus. 



Sepal-wings fringed with spiny teeth. g. R. oblusi/olius. 



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

 I. F. f. i2c/g.) In dry fields and on hillsides throughout N. Am. except 

 the extreme north. Chiefly nat. from Eu. — Pennsylvatiia : Northamp- 

 ton ; Bucks; Lancaster; Franklin; Columbia; Huntingdon; 

 Monroe; Tioga; Chester; Delaware; Alleghi-ny. 



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

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

 in Vt., N. Y. and Pa. — Pemisylvania : TiOGA, Brookfield. 



8 



