252 ASCLEPIADACEAE 



Terr., N. C and Kans. — Pennsylvania: Pike ; Lackawanna; Mon- 

 roe ; Northampton ; Bucks ; Delaware ; Chester ; Lancaster ; 

 Huntingdon ; Erie ; Allegheny. 



12. Asclepias verticillata L. Whorled Milkweed. (Man. p. 744 ; 

 I. F. /. 2g2o.) Drv fields and hills, Me. and Ont. to the N. W. Terr., 

 Fla., Mex. and N. Mex. — Pennsylvania: Luzerne; Northampton; 

 Delaware ; Chester ; Lancaster ; Franklin ; Huntingdon ; 

 Clarion ; Armstrong. 



2. ACERATES Ell. 

 1. Acerates viridiflora (Raf.) Eaton. Green Milkweed. (Man. p. 

 746; I. F. f. 2924.) In dry, sandy or rocky soil, Mass. to Ont., N. W. 

 Terr., Fla. and Tex. — Pennsylvania : Northampton ; Delaware ; 

 Chester; Lancaster; Franklin; Westmoreland; Huntingdon; 

 Alleghany ; Montgomery. 



3. CYNANCHUM L. 

 1. Cynanchum nigrum (L. ) Pars. Black Swallow-wort. (Man. 

 p. 747 ; L F. f. 2gjo.) In waste places, escaped, Mass. to Pa. and Ohio. 

 — Pennsylvania: Philadelphia, Bartram's Garden ; Delaware. 



4. VINCETOXICUM Walt. 

 1. Vincetoxicum obliquum (Jacq. ) Britton. Large-flowered 

 VINCETOXICUM. (Man. p. 74S ; I. F. /. ^'pj^. ) In thickets. Pa. to 

 Ohio, Va. and Ky. — Pefinsylvatiia : Phil.\delphia ; Delaw.\re ; CHES- 

 TER ; Montgomery ; Lancaster ; Franklin. 



5. PERIPLOCA L. 

 1. Periploca Graeca L. (Man. p. 1050.) Nat. of Syria and the 

 Grecian Islands. Adv. or nat. in N. .\m. — Pennsylvania : Philadel- 

 phia. 



Orders. POLEMONIALES. 



A. Stamens 5. 



a. Fruit capsular or baccate : ovary not 4-lobed. 

 Styles or stigmas distinct. 

 Ovary 1-2-celled, or rarely 4-celled : stigmas 2. 

 Ovary 2-celled or 4-celled. 

 Corolla unappendaged within : plants with typical leaves. 



Fam. I. CONVOLVULACEAE. 



Corolla appendaged within : parasitic twining plants with scale-like 

 leaves. Fam. 2. Cuscutaceae. 



Ovary i-celled. Fam. 3. Hydrophyllaceae. 



Ovary 3-celled : stigmas 3. 

 Calyx-lobes imbricated : corolla mostly plaited in the bud. 



Fam. I. CONVOLVULACEAE. 



Calyx-lobes valvate : corolla merely convolute in the bud. 



Fam. 4. POLEMONIACEAE. 



Styles or stigmas wholly united. 

 Median axis of the gynoecium in the same axis as the stem : seeds 



mostly pitted. Fam. 9. Solanace.\e. 



Median axis of the gynoecium not in the same axis as the stem : seeds 

 mostly tuberculate. Fam. 10. Scrophulariaceae. 



