222 NEW YORK STATE MUSEUM 



Key to the New York Milkweeds 



Corona hoods unappendaged, entire at the apex; umbels of flowers sessile; flowers green 



(Green Milkweed) Acerates viridiflora 



Corona hoods each with an incurved horn within (Asclepias) 



Corolla and corona orange; leaves mostly alternate Asclepias tuberosa 



Corolla bright red or purple; leaves opposite 



Flowers one-third of an inch broad or broader; corona hoods one-fourth of an 

 inch high; leaves oblong, ovate or ovate-oblong; hoods oblong and pointed. . . . 



Asclepias purpurascens 



Flowers one- third of an inch broad or less; corona hoods one-twelfth to one-eighth 

 of an inch high 



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



Asclepias incarnata 



Plant pubescent ; leaves oblong Asclepias pulchra 



Corolla greenish, purplish, yellowish or white; leaves opposite 

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



Plants, at least the lower surfaces of the leaves, canescent or tomentose; 



corona hoods short and blunt Asclepias syriaca 



Plants smooth throughout or minutely pubescent above; umbels on long 



stalks 

 Leaves wavy-margined and sessile or nearly so 



Leaves cordate-clasping Asclepias amplexicaulis 



Leaves rounded at the base and short petioled 



Asclepias intermedia 

 Leaves petioled and flat 



Corolla greenish, umbels loose, pedicels drooping 



Asclepias exaltata 



Corolla white; umbels dense Asclepias variegata 



Corolla pink or white, some of the leaves verticillate in fours 



Asclepias quadrifolia 



Leaves narrowly linear, mostly verticillate in threes to sixes ; hoods entire 



Asclepias verticillata 



