134 Trans. Acad. Sci. of St. Louis. 



sist through the winter and send out new branches in the 

 spring; such are Lycopus sinuatus, Lippia lanceolata and 

 Dianthera Americana. 



Propagation hy Adventitious Buds upon Creejnng Roots. 

 Creeping roots of the typical form are produced by Hhus 

 glabra, Ambrosia psilostachya, Onicus undulatus, Apocynum 

 cannabinum, Enslenia albida, Convolvulus arvensis, and 

 Humex Acetosella, some of which are, on this account, bad 

 weeds. Asdepias Cornuti has a thick oblique root producing 

 buds along its surface. Sometimes the new plants thus pro- 

 duced form a crown as in Ascelepias verticillata. 



Solanum Carolinense and several species of Physalis have 

 a very deep slender vertical or horizontal root. Shoots may 

 start from this at considerable depth, and may become slender 

 crowns, thus giving the impression that the plant propagates 

 by rhizomes. 



As to the relation between underground parts of plants and 

 their habitat little can be said. On the stony hills, crown formers 

 are the rule. Species with rhizomes ( C omandra pallida) and 

 creeping roots (Bhus glabra) are rare. Even in these cases 

 crowns are also formed. Rhizomes are not produced on prairie 

 species to any great extent but rather on our mesophyte 

 species inhabiting the rich loam of our woods or moist places 

 along streams and sloughs. All kinds are found about equally 

 in the sand-hills. Of course the perennial weeds of culti- 

 vated soil are those producing rhizomes or creeping roots 

 rather than the crown formers. 



Clematis Pitcheri, Torr. & Gray. A woody vertical crown 

 several inches long covered with fibrous roots. Moist thickets. 



Anemone decapetala, L. Vegetative stems arise from small 

 tubers. After flowering, the tubers send out slender white 

 rhizomes which form tubers at the apex. These tubers pro- 

 duce the vegetative stems of the following spring. Prairie. 



Anemone Virginiana, L. A slowly creeping oblique rhi- 

 zome. Open woods. 



Thalictrum, purpurascens, L. A slowly creeping rhizome, 

 only one-half to one inch long. A strong bud is produced 

 just beyond the base of the vegetative stem. Low prairie or 

 open woods. 



