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 Jtcabane. 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. 



50! >. 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. plantaginifolia, Rich. Mouse-ear everlasting. Noticeable on dry 

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

 soft white when yountr, later green above but hoary beneath, oval tn spatu- 

 late, petioled, 3-veined: flowering stem simple scape-like, 4—8 in. high, 

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

 terminal corymb; scales of involucre whitish. 



