478 STRUCTURE AND LIFE HISTORIES 
which bears a tuft of long silky hairs, whence one of the 
common names, "silk weed." These hairs facilitate the 
distribution of the seeds by the wind (Fig. 362). 
FIG. 362. A milkweed (Asclepias syriaca), with tufted seeds scattering 
from the dehiscing pods. (Photo by Elsie M. Kittredge.) 
420. Convolvulus Family (Convolvulaceae). The fea- 
tures of this family are well illustrated by the genus 
from which it gets its name, Convolvulus, gr bind-weed. 
The five-lobed corolla is bell-shaped, all the parts of the 
flower are in fives, and the pistil two-celled. Most genera 
of the family are trailing or (as the name indicates) 
twining vines (Fig. 363). 
