236 COMPOSITE. (composite family.) 



§ 6. OXYTRIPOLIITM, DC. Scales of the involucre imbricated, without herba- 

 ceous tips, usually very acute, the outer passing into scale-like bracts : pappus soft 

 and capillary : achenia striate. 



39. A. flexubsus, Nutt. Stem zigzag, rigid, forked (6" -20' high); the 

 branches bearing large solitary heads ; leaves linear, thick and fleshy, pointed, entire ; 

 scales of the bell-shaped involucre imbricated in many rows, ovate-lanceolate with 

 awl-shaped points; rays numerous, large, pale purjjle. — Salt marshes on the 

 coast, Maine to Virginia. Sept. 



40. A. linifolius, L. Annual; stem much branched (6' -24' high), the 

 branches bearing numerous racemose or panicled small heads ; leaves linear-lanceolate, 

 pointed, entire, flat, on the branches awl-shaped; scales of the oblong involucre 

 linear -awl-shaped, in few rows ; rays somewhat in two rows, short, not projecting be- 

 yond the disk, more numerous than the disk-flowers, purj)lish. (A. subulatus, 

 Micltx.) Salt marshes, on the coast, Maine to Virginia. Aug. - Oct. 



41. A. angUStus, Torr. & Gr. (Tripolium angustum, Lindl. T. frondo- 

 •sum, Nutt. Also in Siberia, Conyza Altaica, DC, and Brachyactis ciliata, 



Ledtb. ) An annual species related to the last, but with broader leaves, very 

 many minute rays, and more copious pappus : conies from the northwest to near 

 the borders of Wisconsin. 



14. ERIGERON, L. Fleabane. 



Heads many-flowered, radiate, mostly flat or hemispherical ; the narrow rays 

 very numerous, pistillate. Scales of the involucre narrow, nearly equal and 

 little imbricated. Receptacle flat or convex, naked. Achenia flattened, usually 

 pubescent and 2-nerved. Pappus a single row of capillary bristles, with minuter 

 ones intermixed, or with a distinct short outer pappus of little bristles or chaffy 

 scales. — Herbs, with entire or toothed and generally sessile leaves, and solitary 

 or corymbed heads. Disk yellow ; ray white or purple. (Name from ^p, spring, 

 and yepo)i>, an old man, suggested by the hoary appearance of some of the ver- 

 nal species.) 



§ 1. C-rfENOTUS, Nutt. Rays inconspicuous, in several rows, scarcely longer than 

 the pappus: pappus simple: chiefly annuals and biennials. 



1. E. Canad6nse, L. (IIorse-w'eed. Butter-weed.) Bristly-hairy ; 

 stein erect, wand-like (.3° -5° high) ; leaves linear, mostly entire; those from the 

 root cut-lobed ; heads very numerous and small, cylindrical, panicled. — Waste 

 places; a common weed, now widely diffused over the world. July -Oct. — 

 Ligules much shorter than their tube, white. (Nat. in En. &e.) 



2. E. divaricatum, Michx. Diffuse and decumbent (3' -6' high) ; leaves 

 linear or awl-shaped ; heads loosely corymbed ; rays purple : otherwise like No. 1 . — 

 Illinois, Kentucky, and southward. 



3. E. acre, L. Sparsely hairy or smoothish ; stem erect (10' -20' high) ; 

 leaves lanceolate or the lower spatulate-oblong, entire ; heads several or rather 

 numerous, racemose or at length corymbose, nearly hemispherical (4" -5" 

 long) ; rays purplish or bluish, equalling or a little exceeding the copious pap- 

 pus. — Shores of Lake Superior (Dr. Robbins, Prof. Porter, &c.), and northwest- 

 ward. (En.) 



