126 Milkweed ( Asclepiadacece.) [No. 17 



(i) Genus PERIPLOCA, L. 



From two Greek words meaning " twining." 



Resembling Fig. 6l. Twining Milkweed. [P. Grata, Z.] 



Flowers, dark purple, in long axillary clusters. Corolla, 

 flat wheel-shape. Petals, united, very narrow, pointed, 

 very hairy within. Calyx, minute. Sepals, united, 

 narrow, pointed. Stamens, with filaments distinct. 

 Anthers, cohering, and bearded along the back. 

 Throat of the corolla surrounded by a five-parted 

 crown, each lobe tipped with a slender bristle. 



Leaves, three to four inches in length, egg-shape, pointed. 

 Leaf -stem, one third inch in length. 



Fruit, about two inches in length, smooth, many-seeded. 

 Seeds, hairy. A follicle. 



Found, in cultivation, from which it has escaped sparingly 

 in Western New York. 



A woody climber ten to fifteen feet in length. 



(2) Genus VINCETOXICUM, Moench. 



From two Greek words meaning " binding" and " poison." 



Fig. 6l. Black Milkweed. [V. mgrum, Moench] 



Flowers, small, dark purple, in axillary clusters, each cluster 

 on a stem shorter than the leaves. Corolla, flat 

 wheel-shape, five-parted, the crown above its throat a 

 fleshy five- to ten-lobed, flat-disk. 



Leaves, egg-shape to lance-shape, nearly smooth. 

 Fruit and seeds, smooth. 



Found, as a weed escaped from cultivation from New 

 England to Pennsylvania. 



A more or less twining herb. 



