82 COMPOSITE. 



19. TANACETUM. Involucre imbricated. Achenes angular, ter- 

 minating in a large disk, with a membranous margin. Re- 

 ceptacle naked. Sometimes with a short, trifid, ligulate 

 floret. Fl. yellow. 



20. ARTEMISIA. Involucre ovate, imbricated, woolly. Achenes 

 with a minute disk. Pappus none. Receptacle naked. Fl. 

 brownish yellow. 



21. EUPATOBIUM. Involucre imbricated, oblong. Achenes angu- 

 lar or striate. Pappus pilose. Receptacle naked. Heads 

 of few purple florets. 



22. ANTENNARI A. Involucre imbricated, the inner scales coloured 

 at the end. Pappus pilose and clavate on the barren heads. 

 Fertile florets filiform. Receptacle convex, naked. Heads 

 dioecious. 



23. GNAPHALIUM. Involucre hemispherical, imbricated, scales 

 membranous at the end. Pappus pilose. Receptacle flat, 

 naked. Heads with marginal pistillate florets. 



24. FILAGO. Involucre conical, imbricated, scales acuminate, 

 scariose. Pappus pilose. Receptacle conical, scaly at the 

 margin. Outer florets pistillate, mixed with the innermost 

 involucral scales. 



25. PETASITES. Involucre of several herbaceous scales. Pappus 

 pilose. Receptacle naked. Scape bearing a many-headed 

 thyrsus, subdioecious. Fertile florets filiform, in several 

 rows, with 4 or 5 tubular barren ones in the centre ; or in 

 heads with the florets all barren, or 3 4 fertile. FL purple, 

 appearing before the leaves. 



B. Florets of the ray ligulate (Radiate); sometimes in 

 Senecio the ray is absent. 



* Pappus pilose. 



26. TUSSILAGO. Involucre in one row, with membranous mar- 

 gins. Florets of the ray in several rows, narrowly ligulate. 

 Receptacle naked. Fl. all yellow, appearing before the 

 leaves. 



27. ASTER. Involucre imbricated, with a few scales on the ped- 

 uncle. Achenes compressed Receptacle flat, naked and 

 pitted. Fl. of the disk yellow, ray purple. 



28. SOLID AGO. Involucre closely imbricated. Achenes round. 

 Pappus in one row. Receptacle naked. Florets of the ray 

 few. Heads numerous, yellow. 



29. SENECIO. Involucre cylindrical or conical, with numerous 

 scales at the base, brown or withered at the tip. Receptacle 

 naked. Florets all yellow ; sometimes the ray is absent. 



30. DORONICUM. Involucre hemispherical, equal, in two rows. 

 Pappus of the ray-florets absent. Receptacle naked, or nearly 

 so. Fl. yellow, leaves undivided. 



