December 2, 1891.] 



Garden and Forest. 



569 



Solatium nigrum. Bases of white petals green, forming a 

 distinct green eye ; stamens green. 



Poly gala sanguinea and P. cruciata. The flowers are incon- 

 spicuous ; the bracts, the showy part of the flower, change 

 from green to white, and afterward to purple. 



Calla Lily. Greenhouses ; base green, upper portion white. 



Petunias and Four o'clocks of white variety have green tubes. 



Mignonette. Gardens ; green petals have a beautiful snow- 

 white fringe. 



Stock. Gardens ; base of white variety green, as also of 

 many other flowers. 



Examples might be multiplied indefinitely. 



Then, too, the inconspicuous, degraded, weed-like plants, 

 such as our two species of Atriplex, Ambrosia, Amarantus, 

 Acalypha, Ludwigia, Euphorbia, Salicornia, Xanthium, Cus- 

 cuta, Urtica, Pilea, Chenopodium, etc., some of which have 



colored, the development is precisely the same as in the petals 

 and stamens ; the outer edge or margin of the green sepals 

 first discharges its chlorophyl, becoming white, which gradu- 

 ally spreads over the surface to a greater or less extent. 



This tendency to change to white in the sepals is very com- 

 mon ; a complete list, however, would require too much space, 

 and, furthermore, be unnecessary, as a few examples from 

 common plants will suffice for our purpose, namely, Cerastium, 

 Stellaria, Buda, Plantago, Polygonum aviculare, Amarantus-, 

 Arctium, Eupatorium perfoliatum and many other species of 

 the Composites, etc. Commonly, the color of the sepals, after 

 changing, is the same as the petals, as a white Burdock has 

 the scales of the involucre white, a rose-colored Burdock has 

 the scales rose-colored, etc. Thus every part of the flower 

 first changes from green to white, there being ample evidence 

 to prove that the pollen also is at first white. It has been 



Fig. 89. — Rosa Wichuraiana. — See page 570. 



no petals, and in which the colors of the flowers generally are 

 scarcely developed, yet give valuable testimony, for in every 

 example the color of the stamens and pistils at least, and often 

 some part of the sepals, begins in precisely the same order, 

 namely, from green to colorless and faint white ; indeed, in 

 Pilea, which is monoecious, the fertile flower is green, while 

 the staminate has developed to a conspicuous pure white. 

 The yellowish color of Ambrosia is not in the corolla but in 

 the pollen. The tendency, therefore, of these lowly plants is 

 clearly to white and not to yellow. 



The color of the expanded portion of the petal especially 

 attracts the eye, but all parts of the flower, including the calyx, 

 may be colored. As a rule the stamens and styles are colored 

 like the petals, but the anthers frequently are of a different 

 color from the filaments, while the pollen at times differs from 

 both anthers and filaments. When the calyx or involucre is 



used as an argument for yellow as a primary color that the 

 base of the petal of the Rose was yellow. But every one 

 knows that green is composed of blue and yellow, and as 

 either the one or the other element predominates, so will the 

 tone of green be affected. Not only in the fall, but in early 

 summer, the foliage displays various shades of green, and 

 even a blade of grass of one species will differ in shade from 

 that of another, one being, perhaps, a dark or blue-green, the 

 other a lighter or yellowish green ; under these circumstances 

 it is not surprising that, by the eliminating process, a yellowish 

 green, very much thinned down, may be mistaken for a true 

 yellow, especially when the area of color is of the smallest 

 dimensions. The writer has examined many petals of Rosa 

 Carolina and is convinced, notwithstanding the smallness of 

 the light-colored base, that the color immediately below the 

 rose or pink is white and below the white a mere vestige of 



