204 COMPOSITAE 



5. B. vulgata Greene. Bkggae's-ticks. 1°-5° high, more or less 

 pubescent : leaves usually 3-foliolate : leaflets thin, oblong lanceolate, 

 serrate, not stalked : heads long peduncled : acbenes thin, oval-oblong, 

 yellowish brown, 2-awned. — Common in woods, waste places,- etc. July- 

 November. 



Var. puberula (Wiegand) Greene. Leaves densely pubescent. — Fre- 

 quent, especially in wet places. 



6. B. frondosa L. Besembles the last, but leaflets strongly stalked : 

 heads corymbose : aohenes oblong, thick, black, 2-awned. — Common in 

 low grounds. July-November. 



7. B. bipinnata L. Spanish Nbbdlks. 1°-3° high, smoothish : leaf- 

 segments toothed, numerous : achenes quadrangular, 4-awned, much 

 exceeding the involucre. — Common in moist grounds. June-October. 



31. THELBSPBRMA Less. 



Leaves dissected. Heads long- peduncled. Outer involucral scales 

 small, spreading. Achenes oblong-linear, terete, wingless. 



1. T. gracile (Torr.) Gray. Perennial, l°-3° high, glabrous : aohenes 

 bearing two retrorsely-hispid short awns. — Found as a waif near 

 Kansas City and Atherton. — June-August. 



32. GALINSOGA R. & P. 



Leaves opposite. Flowers axillary, peduncled. Involucre imbricated 

 in two series. Achenes angled. 



1. Gr. parviflora Cav. Spreading appressed- pubescent annual : leaves 

 ovate, more or less petioled, serrate : heads 2''''-3'''' broad. — Locally 

 adventized in waste places in Independence. July-October. 



33. PLAVERIA Juss. 



Leaves opposite, sessile. Heads cymose-capitate, few-flowered. Invo- 

 lucre of 2-5 small bracts. Ray usually one, fertile. Achenes linear- 

 oblong, ribbed. 



1. P. anguBtiloUa (Cav.) Pers. Glabrous annual, l°-3° high : leaves 

 lanceolate, serrate. — Has been found as a waif near Courtney, and also 

 near Argentine, Kansas. August-October. 



34. HELENIITM L. Sneezewebd. 



Leaves alternate. Heads corymbose. Involucral bracts small, in about 



one series. Disk globular. Eays several, 3-5-lobed, fertile. 



Leaves oblong-lanceolate, serrate. 1. H. autumnale. 



Leaves long-linear, entire. 2. H. tenuifolium. 



1. H. autumnale L. Perennial, puberulent, l°-4° high : heads about 

 ly broad. — Locally common in moist ground, Lake City, Dodson, Court- 

 ney, Atherton. August-September. 



