Lake Maxinknckee, Physical and Biological Survey 393 

 611. INDIAN HEMP 



APOCYNUM CANNABINUM L. 



Not very common about the lake. The small greenish flowers 

 are not handsome like those of the other species. Found growing- 

 on a hill by Murray's and in flower along the railroad by the ice- 

 houses June 21. 



Family 120. Asclepiadace^. Milkweed Family 

 612. butterfly-weed; pleurisy-root 



ASrLEPIAS TUBEROSA L. 



Quite abundant about the lake, and during the flowering season 

 one of the most conspicuous members of the native flora, the 

 plants growing in clumps. Large clumps in blossom make a glow- 

 ing mass. 



On account of their great range of colors and the oddity of 

 shape, the milkweeds form an interesting and ornamental group 

 of plants ; not on the whole adapted to the uses of the florist and 

 dealer in cut flowers, however, on account of various peculiarities, 

 such as the rapidity with which they wither, the sticky, milky 

 juice, etc. We have orange, purple, white and various other shades 

 represented. Some of the white flowered forms with chaste blos- 

 soms on long slender pedicels, though much less showy than the 

 typical butteryfly-weed, are very attractive. 



The butterfly-weed has an advantage over the other milkweeds 

 in that it has not a milky juice. Most of the plants have orange 

 flowers, but two near the lake, one by Arlington and one south of 

 the birch swamps, had lemon yellow flowers. 



This species has been introduced into seedmen's catalogues and 

 has already obtained some recognition of its value as an ornamental 

 plant. The blossoms vary somewhat in richness of color; one 

 clump seen in Tennessee was unique in that the blossoms deepened 

 in intensity of color as they grew older, so that while the younger 

 heads of flowers were orange yellow the older bunches on the same 

 plant were an intense scarlet. Such an individual would surpass 

 the common form as an ornamental plant. The blossoms of this, 

 as well as of the other milkweeds, abound in small insects (thrips), 

 which hide about the recesses of the flowers, though they probably 

 have little to do with their fertilization. 



This species begins flowering toward the end of July and con- 

 tinues during the summer. The fruit seems to be borne rather 

 scantily considering the abundance of flowers. 



