UMBELLIFERAE 143 



1. B. aquaticum L. Button Snakeroot. Glabrous perennial, 1°-6° 

 high : leaves long-linear, parallel-veined, bristly margined : flowers 

 white : heads 6'''-9'' broad, the bracts pungently pointed.— Not uncom- 

 mon throughout on prairies. July-September. 



7. SANICULA L. Sanicle. 



Involucres foliaceous. Capitate umbellets subtended by small iuvo- 

 lucels. Fruit subglobose, somewhat flattened laterally and covered 

 •with long hooked bristles. 



Styles longer than the bristles. 1. S. gregaria. 



Styles shorter than the bristles. 2. S. Canadensis. 



1. S. gregaria Bicknell. Perennial, 8^-2° high : stems weak : some 

 staminate flowers in separate heads : flowers yellow : leaflets obovate- 

 cuneate, incised serrate.— Not uncommon throughout in rich moist 

 woods. May-July. 



2. S. Canadensis L. Biennial, 6^-2° high : staminate flowers never 

 in separate heads : flowers whitish-yellow : leaflets 3-5, resembling those 

 of the last.— Abundant throughout in woods. May- July. 



8. rOENICULUM Adans. 



Involucre and involucels none. Fruit nearly terete, linear-oblong, 

 prominently ribbed, but not winged. 



1. P. vulgare Gaertn. Fennel. Glabrous perennial, 2^-3° high : 

 leaves decompound.— Rarely escaped from gardens in Kansas City and 

 Independence. May-July. 



9. TAENIDIA Drude. 



Involucre and involucels none. Fruit oval, glabrous, laterally com- 

 pressed, strongly 5-ribbed. 



1. T. integerrima (L.) Drude. Yellow Pimpeenel. 1°-3° high, 

 glabrous. Abundant throughout on rocky hillsides. May-June. 



10. APIASTRUM Nutt. 



Involucre none. Involucels small or none. Fruit ovate, tuberculate, 

 laterally flattened, not ribbed. 



1. A. patens (Nutt.) C. & R. 3M8' high, much-branched, slender 

 and glabrous : leaves much dissected.— In sandy soil and in barrens 

 throughout. Often common. May- June. 



11. CHAEROPHYLLUM L. Cheveil. 



Involucre none. Involucels present. Fruit linear-oblong, 5-angled, 



flattened dorsally. Umbels 2-6-rayed. 



Prostrate spreading. 1- C. procumbens. 



Strictly erect. 2. C. Texensis. 



