COMPOSITES 



443 



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. 560. 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. annuus, 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. ramosus, BSP. Daisy fleabane. Usually annual, with 

 appressed hairs or none: leaves usually entire and narrower: 

 rays white and numerous, twice the length of the involucre. 



E. pulchellus, Michx. Robin's plantain. Perennial leafy- 

 stemmed herb, softly hairy, producing stolons or rooting 

 branches from the base, the simple stems, from a cluster of 

 rather large, roundish, short-petioled, serrate, root-leaves; 

 stem-leaves few, entire, sessile and partially clasping: heads 

 1-7, on long peduncles; rays numerous, linear or spatulate, 

 purplish or pinkish. April to June. 



30. CALLISTEPHUS. CHINA ASTER. 560. Erigeron 



canadensis. 

 Erect, leafy annuals, with large solitary heads bearing 



numerous white, rose or purple rays: scales in several rows or series, 

 usually leafy; torus flat or nearly so, naked; pappus of long and very short 

 bristles. 



C. hortensis, Cass. Common China aster, now one of the commonest of 

 garden annuals, in many forms: leaves sessile and coarsely toothed. China. 



31. ANTENNARIA. EVERLASTING. 



Perennial little herbs with cottony leaves and stems: flowers dioecious, 

 in many-flowered small heads, solitary or racemose or clustered (much 

 resembling Gnaphalium, but distinguished by the dioecious heads); invo- 

 lucre with dry imbricated bracts in several rows, usually woolly-white or 

 colored; pappus in a single row, that of the sterile flowers thickened and 

 plumed at summit. Several confused species, or forms of one species, mostly 

 in open, dry places. 



A. plantaginif olia, Rich. Mouse-ear everlasting. Noticeable on dry 

 soil and in open places, as white cottony patches: stoloniferous root-leaves 

 soft white when young, later green above but hoary beneath, oval to spatu- 

 late, petioled, 3-veined: flowering stem simple scape-like, 48 in. high, 

 bears small, bract-like, appressed leaves, and heads in a small, crowded, 

 terminal corymb; scales of involucre whitish. 



