No. 438.] A r OR THERX GAMOP ETA LOUS FLOWERS. 375 



the changes of color in individual flowers. These color relations 

 will be again referred to under the Boraginacese. 



Of the Hydrophyllaceae 8 species are white and 10 blue. 

 Frequently these latter species revert to white. They are mostly 

 woodland flowers where blue contrasts with the yellowish or 

 brown background. This is a small family intermediate between 

 the preceding family and the Boraginaceae. 



The coloration of few famines is so interesting as that of 

 the Boraginaceae, since the individual flowers often undergo 

 several changes of color, and " seem to recapitulate to us the 

 evolution of their colors." There are some 1500 widely distrib- 

 uted species. The inflorescence is in one-sided scorpioid spikes, 

 racemes, or cymes. The flowers are small and regular, except 

 in Echium, but the corolla varies much in length. In Myosotis 

 and Asperugo the tube is short, and there is a great variety of 

 visitors f while in Borago and Symphytum the flowers are 

 inverted and the honey is accessible only to long-tongued 

 bees. There are 6 yellow, 19 white, 1 purple and 17 blue 

 flowers. Heliotropum polyphyllum is white but in variety leaven- 

 worthii of Florida bright yellow, and in H. cumssavicum (sea- 

 side heliotrope) the corolla is white with a yellow eye, changing 

 to blue. Most of the species are, however, white or blue. The 

 common heliotrope from Peru (//. pentvianutn) has the tube 

 white with the lobes purple, which in fading grow whitish. In 

 this genus yellow and white appear more primitive than purple 

 or blue. Fchinospernum has small bell-shaped flowers, which 

 are visited by flies, bees and moths. E. lappula in the bud is 

 white, red before expanding, and afterwards bright blue. The 

 coloration of Myosotis, one of the simpler genera, is remarkably 

 variable. M. palustris and M. laxa are sky blue with a yellow 

 eye ; M. arvensisln bud has a yellow tube with pale pink corolla 

 lobes, which change to blue and finally fade to white ; M. versi- 

 color is yellow changing to blue and violet, and M. alpcstns 

 produces dark blue, bright blue, reddish, and even snow white 

 flowers. The flowers are visited by many species of flies. 



