ASCLEFIABACEAE. 259 



Philadelphia— Gibson's Point (Mac). Z>eiaware— Lansdovvue on the 

 railroad (Pe.)- 



New Castle — Cedar Swamp, Townsend, Commons. 



Family 6. ASCLEPIADACEAE Lindl. Milkweed Family. 



Erect or decumbent herbs. 



Corona-hoods each with an incurved horn within; leaves mostly oppo- 

 site. 1. Asclepias. 

 Corona-hoods unappendaged or with a thickened, crest-like keel; leaves 

 opposite or alternate. 2. Acerates. 

 Twining vines. 



Anthers tipped with a scarious membrane ; pollen-masses pendulous. 



3. Cynanchum. 

 Anthers merely tipped; pollen-masses horizontal. 4. Fineetoxicitta. 



1. ASCLEPIAS L. Milkweed. 



Corolla and corona orange; leaves alternate or opposite. 

 Stem erect or ascending; leaves nearly all alternate. 



1. A. tuberosa. 

 Stem reclining; leaves, at least the upper, opposite, oblong or oval. 



2. A. deemnhens. 

 OoroUa bright red or purple ; leaves opposite. 



Flowers 2-4 mm. broad; corona-hoods 4-6 mm. high. 

 Leaves lanceolate or linear; hoods oblong, obtuse. 



3. A. lauceolata. 

 Leaves ovate or ovate-lanceolate; hoods lanceolate. 



4. A. rubra. 

 Leaves oblong, ovate or ovate-oblong; hoods oblong, acutish. 



5. A. purpurascenA. 

 Flowers 4-6 mm. broad; corona-hoods 2-3 mm. high. 



Plant nearly or quite glabrous; leaves lanceolate or oblong-laneeo- 



late. 6. A. incarnata. 



Plant pubescent; leaves oblong. 7. A. pulchra. 



OoroUa greenish, purplish, yellowish or white ; leaves opposite or verticillate. 

 Leaves ovate, oblong, ovate-lanceolate, obovate or orbicular. 

 Plants glabrous throughout, or minutely pubescent above. 

 Leaves sessile, clasping, or very short-petioled. 



8. A. amplexicavli*. 

 Leaves manifestly petioled. 



Corolla greenish; umbels loose; pedicels drooping. 



9. A. exaltata. 

 Corolla white; umbels dense. 10. A. variegata. 

 Corolla pink; some of the leaves verticillate in 4's. 



11. A. quadrifolia. 

 Plants, at least the lower surfaces of the leaves, eaneseent or tomen- 

 tose. 12. A. Syriaca. 



Leaves lanceolate, oblong-lanceolate or linear. 13. A. verticillata. 



1. Asclepias tuberosa L. Butterfly-weed, Pleurisy-root. M. p. 741. Dry- 

 fields. Summer. 

 Philadelphia — Byherry, Mart. (B. C), below Gray's Ferry Station, 

 West Fairmount Park (Mac). ifwcfcs— Sellersville (Fr.), Buckingham 

 (Ws.). Montgomery — Shannonville (Cr.), Bryn Mawr (tri.), Spring 

 Mill (Ha.). Delaware— GoUingdale, H. C. Barker (B. C). Williamson 

 (Ke.), Swarthmore (Pn), near Media (B. Sm.), Concord (W. Tr.), 

 C7ie«*<?r— NearWesttown (Le.). ie^^'/i— Coplay (Kr.). Northampton— 

 Easton, Porter (B. C). 



