138 Trans. Acad. Sci. of St. Louis. 



Stenosiphon virgatus, Spach. A strong tap-root with a 

 crown. The bases of the stems persist above ground more or 

 less, and form winter buds. It is thus a semi-shrub. Lime- 

 stone hills. 



Circaea Latetiana, L. Slender rhizomes. Rich woods. 



Opuntia Rafinesquii, Engelm. Forms a tap-root. The 

 first joint throws out lateral joints, and these may root where 

 they come in contact with the soil. Joints mostly perennial. 

 Sand-hills. 



Poly taenia Nuliallii, DC. A flesh}' vertical root sur- 

 mounted by a caudex marked with a series of close rings or 

 leaf-scars. Prairie. 



Peucedanum foeniculaceum, Nutt. One or more caudices 

 from a sunken vertical fleshy root. Stony hills. 



Cicuta maculata, L. A fleshy caudex surmounting a fleshy 

 root which is an inch or two long and half an inch thick, and 

 branched below into several fleshy tuber-like portions. Wet 

 places. 



Sanicula Marylandica , L. A short caudex. Woods. 



Oornus asperifolia, Michx. Woody rhizomes. Woods 

 and thickets. 



Sambucus Canadensis, L. Thick rhizomes. Low woods. 



Triosteum perfoliatum, L. A slowly creeping woody rhi- 

 zome or knotty crown. Open woods. 



Symphoricarpos vulgaris, Michx. An ordinary shrubby 

 root and crown but propagates by long leafy runners or pros- 

 trate stolens, which creep along the surface for a few feet and 

 strike root, forming a new plant. Woods. 



Galium circaezans, Michx. A small crown, with a few 

 fibrous roots. Woods. 



Galium Irifidum, L. var. lati folium, Torr. The slender, 

 decumbent, rooting bases of the stems resemble rhizomes. 

 Woods. 



Galium triflorum, Michx. A crown of tangled stems which 

 throws out buds and fibrous roots. Woods. 



Apocynum cannabinum, L. Buds upon extensively creep- 

 ing horizontal roots. Moist soil. 



Asclepiodora viridis, Gray. A thick woody-fleshy verti- 

 cal or oblique root supporting a strong crown. Prairie. 



