6 CIRCULAR NO. 115, BUREAU OF PLANT INDUSTRY. 
nonhardy types under his observation have “compact. upright- 
growing crowns, with comparatively few buds or shoots below the 
surface of the soil”; while certain of the hardy types are “ char- 
acterized by a more spreading crown, with buds and shoots springing 
from the crown below the surface of the soil.” He has not only 
observed these underground buds, or shoots, as he calls them, but cor- 
relates them with drought resistance and hardiness. Furthermore, 
he notes the tendency of the rhizomes to take root at some distance 
trom the old crown and produce new plants. No detailed descrip- 
tion, however, is given by him of these underground growths or the 
manner or time of their development. 
Oliver, in his work with numerous alfalfas, including natural and 
artificial hybrids of J/edicago sativa and MW. falcata, developed some 
Fic. 1.—A plant of hybrid alfalfa six months from the seedling stage. The prominent 
growths appearing below the crown are rhizomes; in other words, true stems. (I*rom 
Bulletin 258 of the Bureau of Plant Industry, by George W. Oliver.) 
exceedingly interesting material. He finds that there are two gen- 
eral types of rhizomes produced—rooting and nonrooting—and that 
during the early stage of their development they appear to be of the 
same character. He also finds that both types of rhizomes are pro- 
duced most abundantly during the autumn months and that they 
originate at or near the crown of the plant, one case only coming 
under his observation where they were produced below the surface.’ 
in this case the rhizome was at least 3 inches below the crown. 
Oliver gives a rather detailed description of the gross morphology | 
of the rhizomes, their life history, and functions. His descriptions 
and photographs show positively that the underground growths 
which he describes are true and modified rhizomes, according to the 
accepted definition of the term. In other words, they are of stem 
ovens (Hic 13) 
1 Oliver, G. W. Op. cit. 2 Oliver: G: We “Op. cit. ps 22.) Neenioes 
[Cir. 115] 
