COMPOSITAE 199 



1. S. perfoliatum L. CUP PLANT. Stems 4-8 high, square : 

 leaves ovate-cordate, coarsely toothed, scabrous : heads 2 / -3 / wide. 

 Common in moist grounds. June-September. 



2. S. integrifolium Michx. ROSIN 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 X -4 X 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 involucral bracts about ten, linear, loose, the inner oval, appressed. 

 Rays 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- 

 cral bracts in 2-3 series, short, obtuse. Receptacle convex. Ray flowers 

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

 scales. 



1. P. integrifolium L. PRAIRIE DOCK. l-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 Raytown. July-September. 



22. HELIOPSIS Pers. 



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

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

 four-sided. 



1. H. scabra Dunal. FALSE SUNFLOWER. 2-4 high, roughish : 

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

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



23. ECLIPTA L. 



Diffusely spreading herbs. Leaves opposite. Involucral 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-peduncled, W-W broad. 

 Common in wet places along streams. July-October. 



24. RUDBECKIA L. CONE-FLOWER. 



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

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



