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Hitchcock — Studies on Subterranean Organs. 135 



Delphinium azureum, 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 pedatifida, Don. A vertical or oblique caudex. 

 Prairie. 



Silene stellata , Ait. Rather strong root with dichotomously 

 branched crown. Open woods. 



Callirrhoe involucrata, Gray. A spindle-shaped fleshy 

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

 the vegetative stems arise. Prairie. 



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

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

 ground. 



Oxalis cornicidata, L. var. slricta, Sav. Filiform rhizomes. 

 Moist soil. 



Ceanothus ovatus, Desf. Woody root with strong crown. 

 Prairie and stony hills. 



Rhus glabra, L. Creeping roots which produce buds. 

 Thickets and stony hills. 



Rhus Toxicodendron, L. Rhizomes which creep just below 

 the surface. Woods and fence rows. 



Baptisia leucophaea, Nutt. A horizontal woody more or 

 less branched rhizome with strong lateral roots. Prairie. 



Baptisia leucantha, Torr. & Gray. A thick woody slowly- 

 creeping rhizome forming a crown at the apex. Moist 

 meadows. 



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

 thick short knotty horizontal crown. New buds forming at 

 base of old stem. Prairie. 



Psoralea fioribunda, 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. 



