172 American Midland Naturalist Monograph No. 7 



22. Fruit with equal, prominently corky ribs: stylo- 

 podium depressed; oil-tubes 1-3 in each interval 



18. Sium 



21. Leaves remotely and irregularly dentate usually only 



above the middle, or entire 27. Oxypolis 



17. Involucral bracts none, or few and soon deciduous. 

 23. Flowers white; fruit somewhat flattened laterally. 



24. Leaflets serrate 19. Cicuta 



24. Leaflets not serrate 8. Perideridia 



23. Flowers yellow; fruit flattened dorsally. 



25. Leaf-segments filiform; slender annuals 21. Anethum 



25. Leaf-segments broader. 



26. Stem terete; fruit with thick corky margin, obscure 



ribs and numerous oil-tubes; plants perennial 



22. Poly taenia 



26. Stem grooved; fruit with filiform dorsal ribs, thin 



wings, and solitary oil-tubes; stout biennial 



24. Pastinaca 



1. Eryngium L. — Rattlesnake-master 



E. yuccifolium Michx. Meadows, roadsides, and prairie soil; prob- 

 ably in every county, but not particularly abundant. Jidy-Aug. 



2. Daucus L. — Carrot 



1. Biennial, 30-90 cm tall, with a taproot; umbel 5-12 cm broad, the 

 outer rays 2.5-8 cm long; central flower purple or rose; ultimate 

 segments of leaves lanceolate : fields, roadsides, waste places, 

 very common; nat. from Ein\ July-Nov. Carrot D. carota L. 



1. Annual, 10-30 cm tall; imibel 2-5 cm broad, the rays 4-12 mm 

 long; all flowers white; ultimate segments of leaves linear; Perry 

 Co., R. A. Evers in 1949; Jackson Co., R. H. Mohlenbrock in 

 1954 D. pusillus Michx. 



3. Torilis Adans. — Hedge Parsley 

 T. japouica (Houtt.) DC. Waste ground and edges of woods, 

 occasional; nat. from Eur. [T. anthriscus (L.) Gmel.]. 



4. Sanicula L. — Sanicle. Snakeroot 



1. Styles longer than the bristles of the fruit, recurved. 



2. Petals greenish-white; sepals subulate; fruit sessile, 6 mm long; 

 woods, local; chiefly in the n. half of 111. May-June. Black 

 Snakeroot S. marilandica L. 



2. Petals yellowish-green; sepals oval or lanceolate; fruit pedicel- 



late, 3 mm long; woods, common. May-Jime. Common 



Snakeroot ..S. gregaria Bickn. 



1 . Styles shorter than the bristles. 



3. Mature fruit globose, 4-5 mm long; staminate flowers short- 



pedicelled; woods, local. June-Sept. Short-styled Snakeroot 

 - S. canadejisis L. 



