THE AMERICAN BOTANIST 107 



bears both purple and white infloresences on the same plant. 

 Cases of albinism are common in many species, but it appears 

 to be rare for a single plant to bear both normal and albino 

 flowers. Other cases are known, however. The cross be- 

 tween the purple-flowered alfalfa {Medicago sativa) and the 

 yellow-flowered Medicago falcata results in individuals that 

 may bear yellowish-white, deep yellow, lilac and greenish- 

 violet flowers. 



Colors of Aster Florets. — It is interesting to notice 

 how each species of aster changes the tints of its disk florets. 

 Late in the season I chanced to look closely at the heads of A. 

 ericoides and observed that the little flowers are in bud when 

 they are bright yellow ; as soon as they open they begin to 

 darken and eventually are red-brown. The disk buds of A. 

 Lowrieanus are cream color and become purple when full- 

 blown florets. Is it a sign to tell the bees that they are past 

 being a storehouse for visitors? I brought some into the 

 house and the yellow buds of ericoides opened and yellow 

 florets were to be seen ; the pale buds of Lowrieanus gave way 

 to pale blossoms. Apparently the flowers refuse to change 

 their hue if the pollen is not brushed away. — Nell McMiurray. 



