COMPOSITE 



411 



and pistillate: scales of involucre close, usually not green and leaf -like: 

 torus not chaffy: akene nearly cylindrical, ribbed, with pappus of many soft 

 bristles. Of goldenrods there are many species. They are characteristic 

 plants of the American autumn. They are too critical for the beginner. 



27. Inula, elecampane. 



Large and tall coarse perennial herbs, with large, showy yellow flower- 

 heads 2-4 in. diameter, sunflower-like: leaves large, simple, alternate, 

 and also radical in clumps: heads contain both perfect tubular, and pistil- 

 late ray florets, in one row: receptacle not chaffy: akenes 4-5-ribbed : 

 pappus in one row, bristles hair-like. 



I. Hel6nium, Linn. Four to 6 ft., rising from a clump of large, ovate, 

 dock-like leaves on heavy petioles: stem leaves sessile or clasping; heads 

 solitary, terminal: involucre bracts ovate, leaf -like, woolly. Weed in damp 

 pasture and along roadside. Summer. 



28. Aster, aster. Fig. 227. 



Perennial herbs, with narrow or broad leaves: heads with several to 

 many white, blue or purple rays in a single series, the ray florets fertile: 

 scales of involucre overlapping, usually more or less green and leafy: torus 

 flat: akenes flattened, bearing soft, bristly pappus. Asters are conspicuous 

 plants in the autumn flora of the country. The kinds are numerous, and it' 

 is difficult to draw specific lines. The beginner will find them too critical. 



29. ERlGERON. Fleabank. 



Annual, biennial or perennial erect herbs, with simple, sessile leaves: 

 heads few- to many -flowered : rays numerous in several rows and pistillate: 

 scales of involucre narrow and equal, scarcely overlapping, not green-tipped: 

 torus flat or convex, naked: pappus of soft bristles. 

 a. Rays very inconspicuous. 

 E. Canadensis, Linn. Horse-weed. Mare's-tail. Fig. 501. 

 Tall, erect, weedy, hairy annual, with strong scent : leaves 

 linear and mostly entire or the root-leaves lobed: heads small 

 and very numerous in a long panicle, the rays very short, 

 aa. Rays prominent : common fleabanes. 

 E. dnnuus, Pers. Usually annual, 3-5 ft., with spreading 

 hairs: leaves coarsely and sharply toothed, the lowest ovate 

 and tapering into a margined petiole: rays numerous, white or 

 tinged with purple, not twice the length of the involucre. 



E. strigosus, Muhl. Usually annual, with appressed hairs 

 or none: leaves usually entire and narrower: rays white and 

 numerous, twice the length of the involucre. 



E. bellidifdlius, Muhl. Robin's plantain. Perennial leafy- 

 stemmed herb, softly hairy, producing stolons or rooting 

 601. Erigeron ^•'■'"''^fis from the base, the simple stems, from a cluster 

 Canadensis, o^ ratlier large, roundish, short-petioled, serrate, root leaves: 



