68 The Ohio Naturalist [Vol. XIII, No. 4, 



There is one prickly-pear, Opuntia sp., with fragrant flowers 

 and edible fruit which ripens in late autumn. It is quite common 

 especially in patches of buffalo-grass or in gumbo patches where 

 it does not have to meet the competition of the Andropogons. 

 On the very highest hills Cactus missouriensis (Sweet.) Ktz., the 

 Missouri cactus, grows although it is quite rare. 



Besides the grasses, the most characteristic plants of the prairie, 

 as stated above are perennial geophytes, mostly crown -formers 

 with deep taproots. Of special prominence are Psoralea floribunda 

 Nutt., many-flowered Psoralea, and Psoralea argophylla Pursh, 

 silver-leaf Psoralea. Both species are tumbleweeds, being sepa- 

 rated from the perennial base by means of cleavage planes devel- 

 oped in the stems near the ground. Psoralea esculenta Pursh, 

 prairie-apple, with its thickened root is also common. In the 

 spring and early summer, three species of wild-indigo are found 

 here and there as conspicuous members of the flora, nameh', 

 Baptisia australis (L.) R. Br., Baptisia bracteata Ell., and Baptisia 

 leucantha T. & G. having blue, cream-colored, and white flowers 

 respectively. 



Other large and conspicuous species are as follows : 



Verbena stricta Vent. Hoary Vervain. 



Verbena hastata L. Blue Vervain. 



Vernonia baldwini Torr. Baldwin's Ironweed. 



Euphorbia marginata Pursh. Snow-on-the-mountain. 



Carduus undulatus Nutt. Wavy-leaf Thistle. 



Artemisia gnaphalodes Nutt. Prairie Mugwort. 



Artemisia ludoviciana Nutt. Lobed Mugwort. 



Glycyrrhiza lepidota Pursh. Wild Liquorice. 



Helianthus maximiliani Schrad. Maximilian's Sunflower. 



Helianthus subrhomboideus Rydb. Rhombic-leaf Sunflower. 



Heliopsis scabra Dun. Rough Oxeye. 



Lespedeza capitata Mx. Round-headed Bush-clover. 



Allionia linearis Pursh. Narrow-leaf Umbrella-wort. 



Ambrosia psilostachya DC. Western Ragweed. 



Acuan illinoensis (Mx.) Ktz. Illinois Acuan. 



Salvia pitcheri Torr. Pitcher's Sage. 



Meibomia — several species. 



Lactuca — several .species. 



Hieracium longipilum Torr. Long-bearded Hawkweed. 



Nabalus asper (Mx.) T. & G. Rough Rattlesnake-root. 



Onagra biennis (L.) Scop. Common Evening-primrose. 



Gaura parviflora Dougl. vSmall-flowered Gaura. 



Gaura biennis L. Biennial Gaura. 



Onosmodium carolinianum (Lam.) DC. Slaggy False-gromwell. 



Grindelia squarrosa (Pursh) Dun. Broadleaf Gum-plant. 



Cuscuta paradoxa Raf. Glomcrata Dodder, a conspicuous parasite mostly 

 on the tall herbs of the sunflower family, growing in ravines but occa- 

 sionally on the upland. 



