. .' ASGLEPIADACEAE. 259 



Philadelphia— Gibson's Point (Mac). Delaware^- Lansdowne on the 

 railroad (Pe.). h:»;' u. ; 



New C.<w^fi.- T 'Cedar Swamp, Townsend, Conymons* 



Family 6. ASOLEPIADACEAE Lindl. Milkweed Family. 



Erect or decumbent herbs.. ■ . ■>,■:. 



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



S1 * e - ;,,,.. 1. AsaleniJas, 



Corona-hoods unappendaged or with a thickened, crest-like keel'; 1 leaves 

 opposite or alternate.. %, Acerates. 



Twining vines. 



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



3. Cynanchum. 

 Anthers merely \tipped'; polien-masses, horizontal. • 4, Vincetoxicum. 



1. A8CLEPIAS L. Milkweed. 



Corolla and corona orange; leaves alternate or opposite. 

 Stem erect or ascending ;, lea.ves nearly ,all alternate. 



1. A. tuberosa. 

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



i ■'. . i . . im i . , , 2. A. decumbent. .:. 



Corolla bright red or purple; leaves opposite. 



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



Leaves lanceolate or linear ; hoods' oblong, ; oWuse. .'< 



3. A. lanceolate 

 Leaves ovate ..or ovate-lanceojate ; hoods lanceolate. 



' 4. A. rubra. 

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



■".. i .•'.•" ■ 5. A. p-urpurascens. 



i Flowery 4-6 mm. broad; oora,na;hii|o,ds 2-3 mm. high. 



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

 late. 6. A: incarnata. 

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

 Corolla greenish, purplish, yellowish or white ; leaves opposite or veuticillate. 

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



Plants glabrous throughout, or minutely ptfbescent above. ,: 



Leaves sessile, clasping, or very short-peteMed. 



. .. i 8. A. amplexicaulis. 



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., qnndrifolia. 



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

 tose. 12. A. Syiiaca. 



Leaves lanceolate, oblong-Sa/nceolate or linear. 13. A. veriicillata. 



1. Asclepias tubeeqsa L. Butterfly -weed. Pleurisy -roofr. M. p. 741. Dry 

 fields. Summer. . 



Philadelphia — Byberry, Mart. (B. C), below Gray's Perry Station, 

 West Fairmonnt Park (Mac). Bucks— Sellersville (Fr.), Buckingham 

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

 Mill (Ha.). Delaware— Collingdale, H. 0. Barker (B. C), Williamson' 

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

 ■Chester— Near Westtown (Le.)i Lehigh— Coplay (Kr.). Northampton— 

 Baston, Porter i(B. C). 



