VARIATION AND CORRELATION IN THE FLOWERS OP 

 LAGERSTROEMIA INDICA. 



BY J, ARTHUR HARRIS. 



Lagerstroemia indica, frequently grown as an ornamental 

 shrub in the United States under the common name of Crape 

 Myrtle, is a member of a genus of about thirty species*, be- 

 longing to the Lythraceae, a family of considerable interest 

 to floral ecologists through the researches of Darwin. For 

 the most part the genus is confined to the oriental and aus- 

 tral Asian region, and this species seems to be the only one 

 extensively cultivated for ornamental purposes. 



Briefly, the structure of the flower is as follows: The 

 petals are unguiculate, with an oval to orbicular crispate 

 limb. The numerous stamens have filiform filaments and 

 elliptical anthers with broadly pulviniform connectives. The 

 greater number of the stamens are bright yellow in color, but 

 one in front of each sepal is usually larger, both as to fila- 

 ment and anther, and of a reddish instead of a yellow 

 color. In young buds the anthers are not distinguishable 

 by their color, both kinds being a Hght yellow. The charac- 

 teristic colors arc developed as the buds grow older. 



Biological observations on the flowers are very few. Dar- 

 win, in his classic paper on Lythrum'f, was the fiirst to notice 

 the species in this respect. He found it strongly variable in 

 the number of stamens, and suggested as a cause its growth 

 in the hothouse. He usually found five long stamens with 

 thick flesh-colored filaments bearing anthers producing green 

 pollen, and from 19 to 29 smaU stamens with yellow filaments 

 and anthers producing yellow pollen. In other cases, how- 

 ever, he found those with only one to four larger stamens with 

 anthers producing green pollen, which in some cases was re- 

 placed by that which was yeUow in color; one anther, indeed, 

 offering the peculiar case of onelocule containing bright yellow 



* Koehne, E. Lythraceae. Das Pflanzenreich. 19. 1903. 

 t Darwin, C. Jour. Linn. Soc, Bot. 8 : 176. 1865. 



' (97) 



