Hitchcock — Studies on Subterranean Organs. 135 



Delphinium azxireum, Michx. A crown from a cluster of 

 fascicled roots, Prairie. 



Helianthemum Canadense, Michx. New stems from base 

 of old. Upland woods. 



Lechea tenuifolia^ Michx. A small but strong tap root 

 supporting a crown of small stems. Upland woods. 



Viola pedatijida, Don. A vertical or oblique caudex. 

 Prairie. 



Silene stellata, Ait. Rather strong root with dichotomously 

 branched crown. Open woods. 



CalUrrhoe involucrafa, Gray. A spindle-shaped fleshy 

 root an inch or more thick, from the sunken summit of which 

 the vegetative stems arise. Prairie. 



Oxalis corniculata, L. A tap-root with a crown but the 

 decumbent bases of the stem may root more or less. Open 

 ojround. 



Oxalis corniculafa, L. var. stricta, Sav. Filiform rhizomes. 

 Moist soil. 



Ceanothus ovafus, Dest. Woody root with strong crown. 

 Prairie and stony hills. 



Bhus glabra, L. Creeping roots which produce buds. 

 Thickets and stony hills. 



Bhus Toxicodendron, L. Rhizomes which creep just below 

 the surface. Woods and fence rows. 



Baplisia leucophaea, Nutt. A horizontal woody more or 

 less branched rhizome with strong lateral roots. Prairie. 



Baplisia leiccantha, Torr. & Gray. A thick woody slowly- 

 creeping rhizome forming a crown at the apex. Moist 

 meadows. 



Baplisia australis, R. Br. A woody root surmounted by a 

 thick short knotty horizontal crown. New buds forming at 

 base of old stem. Prairie. 



Psoralea Jloribunda, Nutt. A strong vertical fleshy root, 

 often branched below. Several stems arise from the summit 

 which is several inches below the surface. Prairie. 



Psoralea argophylla, Pursh. A long woody or somewhat 

 fleshy tap-root sunken several inches below the surface. 

 From the crown at apex, one or more slender vegetative stems 

 are sent up. Prairie. 



