FLORA OF MICHIGAN. 113 



*76'2. F. saiiibiicifolia, Lam. Black Ash. Th. 



Common. 



LIV. APOCYNACE.E. DOGBANE FAMILY. 



263. APOCYNUM, Tourn. DOGBANE. INDIAN HEMP. 



*763. A. aiidrossemifolium, L. Spreading Dogbane. Th. 



Borders of woods. Common. 



*764. A. caimabimim, L. Indian Hemp. Th. 



Low grounds. Exceedingly variable in sine, habit, shape of leaves, pubescence, etc. De Candolle's 

 varieties glaberrimum and pubescens occur, but also intermediate forms, rendering useless any sub-spe- 

 cific names. Common. 



LV. ASCLEPIADACEJE. MILKWEED FAMILY. 



264. ASCLEPIAS, L. MILKWEED. SILKWEED. 



*765. A. tuberosa, L. Butterfly- weed. Pleurisy-root. 

 Sandy soil. Ranges from Canada to Florida, and from the Saskatchewan Valley to Texas. Common. 



766. A. purpurasceiis, L. Purple Milkweed. C. & S. 



Woods. Ann Arbor, -Winch. Cat. ; Ionia Co.; Clinton Co.; Flint; Macomb Co. Infrequent. 



*767. A. iiicarnata, L. Swamp Milkweed. Th. 



Banks of streams. Common. 



*768. A. Corimti, Decaisne. Common Milkweed or Silkweed. Th. 



Fields. Common. 



769. A. obtusilblia, Michx. 



Baldwin, Lake Co.,-Dr. Beal; Sturgis, Barron Lake,-C. F. Wheeler, 1890; Niles,-O. J. Stilwell. 

 Rare. 



*770. A. pliytolaccoides, Pursh. Poke-Milkweed. C. & S. 



Moist grounds. Ann Arbor; Ft. Gratiot, Winch. Cat.; Ionia Co.; Flint; Macomb Co. Infrequent. 



771. A. verticillata, L. 



Barrens, S. Mich., Wright Cat.; Monroe Co., Grand Rapids, Wheeler; Washington, Macomb Co., 

 Dr. D. Cooley. 



265. ACERATES, Ell. GREEN MILKWEED, 



772. A. longifolia, Elliott. 

 South Haven, Bailey. 



773. A. viridiflora, Ell. C. & S. 



Grand Rapids, Geo. D. Sones ; Ft. Gratiot, Winch. Cat.; S. W., Wright Cat. Rare. 

 266. VINCETOXICUM, Moench. 



*774. V. NIGRUM, Moench. 

 Escaped from cultivation on College grounds. 



|LVI. GENTIANACEJE. GENTIAN FAMILY. 



267. ERYTHR^EA, Richard. CENTAURY. 



*775. E. CENTAURIUM, Pere. Centaury. 

 Agricultural College grounds, Bailey. The only locality known in the State. 



[A. VIRIDIFLORA, Ell. var. LANCEOLATA, Gray. 



On a sand beach at Point Edward, foot of Lake Huron, Macoun.J 



