COMPOSITE. 129 



into short margined petioles. Bays usually 10. Thickets 

 and river-banks. 



8. H. gigante'US, L. Stem tall, hairy or rough, branch- 

 ing above. Leaves lanceolate, pointed, serrate, very rough 

 above, hairy below, narrowed and ciliate at the base. 

 Heads somewhat corymbed, not large. Disk yellow ; rays 

 pale yellow, 15-20. Low grounds, western and south- 

 western Ontario. 



9. H. tubero'SUS, L., (JERUSALEM ARTICHOKE) has escaped 

 from cultivation in some places. It is at once recognized 

 by its tubers. 



38. ACTINOM'ERIS, Nutt. 



A. squarro'sa, Nutt. Stem hairy, tall, commonly winged 

 above. Leaves oblong to ovate-lanceolate, pointed at both 

 ends. S. W. Ontario. 



39. CORJEOP'SIS, L. TiCKSEED. 



1. C. tinetO'ria, Nutt. Stem smooth, 2-3 feet high. 

 Leaves once- or twice-pinnately divided, the lobes narrow. 

 Pappus none. Achenes oblong. Rays yellow, brown-tinted. 

 N. W. 



2. C. triehosperm'a, Michx., var. tenuilo'ba, Gray. 

 (TICKSEED SUNFLOWER.) Stem smooth, branching. Bays 

 golden-yellow. Leaves short-petioled, pinnately divided, the 

 segments serrate. Achenes narrowly wedge-oblong, 2-toothed. 

 Swamps, S. W. Ontario. 



3. C. vertiellla'ta, L. Glabrous. Leaves ^essile, divided 

 into 3 sessile leaflets (appearing whorled), these pinnately 

 dissected into very narrow divisions. Damp places, S. W. 

 Ontario. 



4. C. trip'teriS, L. Smooth. Stem tall, corymbed above. 

 Leaves petioled. pinnately divided, the divisions lanceolate, 

 acute, entire. Disk turning brownish. Damp places, S.W 



Ontario. 



4O. GAILLARJ>'IA, Fong-. 



G. arista'ta, Pursh. Bough-hairy, about 2 feet high. 

 Leaves lanceolate to oblanceolate, entire to coarsely pinnat- 

 ifid. Dry soil, N. W. 



