From Blue to Purple 



do, especially in closely allied species ? "The causes which have 

 led to the different forms of leaves have been, so far as 1 know," 

 says Sir John Lubbock, "explained in very few cases : those of 

 the shapes and structure of seeds are tolerably obvious in some 

 species, but in the majority they are still entirely unexplained ; 

 and, even as regards the blossoms themselves, in spite of the 

 numerous and conscientious labors of so many eminent naturalists, 

 there is as yet no single species thoroughly known to us." 



Ground Ivy or Joy; Gill-over-the-Cround ; 

 Field Balm ; Creeping Charlie 



{Glecoma hederacea) Mint family 

 {Nepeta Glechoma of Gray) 



Flowers — Light bluish purple, dotted with small specks of reddish 

 violet ; growing singly or in clusters along stem, seated in 

 leaf axils ; calyx hairy, with 5 sharp teeth ; corolla tubular, 

 over ^ in. long, 2-lipped, the upper lip 2-lobed, lower lip with 

 3 spreading lobes, middle one largest ; 4 stamens in pairs under 

 upper lip ; the anther sacs spreading ; i pistil with 2-lobed 

 style. Stem: Trailing, rooting at intervals, sometimes 18 in. 

 long, leafy, the branches ascending. Leaves: From J^ to i J4 

 in. across ; smooth, rounded, kidney-shaped, scallop-edged. 



Preferred Habitat — Waste places, shady ground. 



Flowering Season — March — May. 



Distribution — Eastern half of Canada and the United States, from 

 Georgia and Kansas northward. 



Besides the larger flowers, containing both stamens and pistils, 

 borne on this little immigrant, smaller female flowers, containing 

 a pistil only, occur just as they do in thyme, mint, marjoram, and 

 doubtless other members of the great family to which all belong. 

 Muller attempted to prove that these small flowers, being the least 

 showy, are the last to be visited by insects, which, having pre- 

 viously dusted themselves with pollen from the stamens of the 

 larger flowers when they first open, are in a condition to make 

 cross-fertilization certain. So much for the small flower's method 

 of making insects serve its end ; the larger flowers have another 

 way. At first they are male ; that is, the pistil is as yet undevel- 

 oped and the four stamens are mature, ready to shed pollen on 

 any insect alighting on the lip. Later, when the stamfens are 

 past maturity, the pistil elongates itself and is ready for the ecep- 

 tion of pollen brought from younger flowers. Many biwisoms 

 are male on the first day of opening, and female later, to protect 

 themselves against self-fertilization. 



44 



