CAEDUACEAE. 297 



14. A. dumosus L. Stems 3-9 dm. tall, glabrous or very nearly so, paniculately 

 much-branched: leaf-blades firm, those of the stem lin'ear or liDear-Ianeeolate, 

 2-7 cm. long, entire, acute or obtusish, roughly margined, often reflexed, those 

 of the branches very numerous, small and scale-like, those of the basal 'leaves 

 spatulate, dentate: heads 8-14 mm. broad, terminating the usually divergent 

 slender branches and branchlets, usually numerous: involucre broadly campanu- 

 late; bracts linear-subulate, appressed, in about four series, obtuse, with 

 green spatulate tips tapering at the apex: ray-flowers 15-30; ligules' white 

 (rarely pale-pink or pale-violet), 4 mm. long: pappus white: achenes minutely 

 pubescent. — S. Occasional, on rocky banks of streams. — Schists. 



15. A. multiflonis Ait. Stems 3-20 dm. tall, strict, much-branched and bushy, 

 the branches ascending or spreading: leaf -blades rigid, linear, entire, mostly 

 obtuse, sessile or slightly clasping at the base, strigose or glabrate, those of 

 the cauline leaves 1-2.5 cm. long, those of the branches very small and 

 crowded: heads 6-8 mm. broad, densely crowded, nearly sessile: involucre 

 turbinate, 4-6 mm. high; bracts coriaceous, pubescent, in 3 or 4 series, their 

 short green tips obtuse or mucronate, spreading: ray-flowers 10-20; ligules 

 white, 3-4 mm. long: pappus becoming brownish-white. — Common, in thick- 

 ets and on banks. 



16. A. lateriflorus (L.) Britton. Stems 3-15 dm. tall, puberulent or nearly 

 glabrous, slender, divergently branched, often bushy: basal leaves few; blades 

 ovate, short-petioled; cauline leaves numerous; blades broadly lanceolate or 

 oblong-lanceolate, 5-12 cm. long, mostly acuminate, serrate, those of the 

 branches smaller, oblong or linear-oblong: heads 6-10 mm. broad, racemosely 

 unilateral on the branches, short-peduncled or sessile, usually numerous and 

 crowded: involucre turbinate; bracts linear-oblong, obtuse or acutish, in about 

 4 series, their short green tips appressed or slightly spreading: ray-flowers 

 numerous; ligules short, whitish or pale-purple, rounded at the apex: disk- 

 flowers purple: pappus white. — Lower Susquehanna valley. Occasional, on 

 islands and shores. 



17. A. vimineus Lam. Stems 6-15 dm. tall, glabrous or nearly so, slender, 

 divergently branched : cauline leaves linear-acuminate, 7-12 cm. long, regularly 

 minutely hack-serrate, slightly narrowed at the sessile base, those of the 

 branches much smaller: heads very numerous, 6-10 mm. broad, generally 

 densely racemose-secund, short-peduncled: involucre broadly turbinate; bracts 

 linear, acute or acutish, green-tipped, appressed: ray-flowers numerous; ligules 

 about 4 mm. long, narrowly linear, white, often roseate in fading: pappus 

 white. — M. Occasional, in moist grassy places. — Limestones. 



18. A. ericoides L. Stems 3-9 dm. tall, glabrous or very nearly so. paniculately 

 branched, usually bushy, the branches racemose, and the branchlets often some- 

 what secund : leaf -blades firm or rigid, those of the basal leaves spatulate, 

 obtuse, dentate, narrowed into margined petioles, glabrous or eijiate. those of 

 the cauline leaves narrowly linear, acute, entire, 2-7 cm. long, those of the 

 branches linear-subulate, numerous: heads usually very numerous, 8-12 mm, 

 broad : involucre campanulate to hemispheric ; bracts coriaceous, closely ap- 

 pressed, lanceolate or linear-lanceolate, abruptly acute or acuminate, green- 

 tipped, in about 3 series: ray-flowers 15-25; ligules white or purplish-tinged: 

 pappus white. — Common, in fields and waste places. 



19. A. Tradescanti L. Stems 6-15 dm. tall, slender, paniculately branched, the 

 branches usually ascending and often pubescent in lines: cauline leaves 

 numerous; blades linear-lanceolate or lanceolate, 7-15 cm. long, acuminate, 

 narrowed to the sessile base, glabrous or nearly so on both sides, commonly 

 thin, sharply serrate in the middle with low teeth, or sometimes entire: heads 

 very numerous, racemose but not secund on the branches, 10-16 mm. broad: 

 involucre hemispheric to broadly turbinate, 4-6 mm. high; bracts linear, acute, 

 appressed, green-tipped, in 4 or 5 series: ray-flowers numerous; ligules white 



