COMPOSITAE 199 



1. S. perfoUatum L. Cup Plant. Stems 4°-8° high, square : 

 leaves ovato-oordate, coarsely toothed, scabrous : heads 2'-3' wide. — 

 Common in moist grounds. June-September. 



2. S. integiifolium Michx. Eosin Weed. Stems almost terete, 2°-5° 

 high : leaves ovate-lanceolate, denticulate, rough or smooth : heads l'-2' 

 broad. — Common in dry grounds, mostly in the southern part. June- 

 September. 



3. S. laciniatum L. Compass Plant. Stems terete, 3°-12° high, 

 rough- bristly : leaves largely basal, oblong- ovate in outline, pinnately 

 parted : heads 2'-4' broad. — Common on prairies, mostly in the southern 

 part. June-September. 



20. ENGELMANNIA T. & G. 



Perennial herbs with alternate leaves and paniculate heads of flowers. 

 Outer involuoral bracts about ten, linear, loose, the inner oval, appressed. 

 Eays 8-10. Achenes obovate. Pappus a short crown. 



1. B. pinnatifida T. &G. l°-2° high, hirsute ; leaves oblong in out- 

 line, pinnatifid. — Has been found as a waif at Sheffield. June. 



21. PARTHENIUM L. 



Perennial herbs with alternate leaves and corymbose flowers. Involu- 

 oral bracts in 2-3 series, short, obtuse. Receptacle convex. Eay flowers 

 five, their ligules short. Achenes compressed, margined. Pappus of 2-3 

 scales. 



1. P. integrifolium L. Pbairik Dock. 1°-3° high, from thick root- 

 stocks, minutely pubescent to glabrous : leaves oval-oblong, crenately 

 toothed, rough : heads numerous. — Very rare in dry woods west of Lee's 

 Summit and south of Eaytown. July-September. 



22. HELIOPSIS Pers. 



Perennial herbs. Involuoral scales in two or three rows, spreading. 

 Pappus none or a few teeth. Eay achenes three-sided. Disk achenes 

 four-sided. 



1. H. scabra Dunal. False Sunflower. 2°-4° high, roughish : 

 leaves ovate, petioled, sharply serrate : heads 2' broad. — Frequent in dry 

 grounds, especially in the southern part. June-September. 



23. ECLIPTA L. 



Diffusely spreading herbs. Leaves opposite. Involuoral scales in two 

 series. Achenes of ray-flowers 3-sided, those in the disk compressed. 



1. E. alba (L.) Hassk. Mud Weed. Annual, roughish : leaves ob- 

 long-lanceolate, sessile, serrate : heads short-pedunclcd, "if'-W broad. — 

 Common in wet places along streams. July-October. 



24. RUDBECKIA L. .Cone-flower. 

 Involuoral scales in two rows, spreading. Achenes four-angled or ter- 

 ete. Pappus none, or a crown-like border, or of few small teeth. 



