352 LXXV. COMPOSITZA. XANTHIUM, 
56. FILAGO. Tourn. 
Apparently trom the Lat. ila, on account of the cottony fibres or hairs. 
Heads heterogamous ; involucre of a few villous scales; marginal 
flowers 2; receptacle columnar, naked at the apex, chaffy at base; 
achenia terete ; central ones with a hairy pappus.—Downy-canescent 
herbs. Lvs. alternate, entire. 
F, Germanica. (Gnaphalium. Linn.) German Cud-weed. 
St. dichotomous or proliferously branched above; ls. linear-lanceolate, 
acute, crowded, erect; Ads. few-flowered, in dense, capitate clusters, terminai 
and lateral; scales cuspidate, passing insensibly into the paleze of the receptacle, 
each with a pistillate flower in the axil—qd) A European plant, sparingly natu- 
ralized in fields androadsides, Ms. Stem 6—10'high. Scales straw-color, with 
a green line outside. July—Oct. 
57. ERECHTITES. Raf. 
G7. epexS@, to trouble ; the species are troublesome weeds. 
Flowers all tubular, those of the margin pistillate, of the disk per- 
fect; involucre cylindrical, simple, slightly calyculate; receptacle 
naked ; pappus of numerous fine, capillary bristles —@® Lws. simple, 
alternate. Els. corymbose, whitish. 
E. nieracirouius. Raf. ieeuicie hieracifolius. Linn.) Fire-weed. 
St. paniculate, virgate; lvs. oblong, amplexicaul, acute, unequally and 
deeply toothed with acute indentures ; invol. smooth; ach. hairy.—@ A well 
known, rank weed, growing in fields, (Can. and U.S.) particularly and abun- 
dantly in such as have been newly cleared and burnt over, and hence it is called 
fire-weed. Stem thick and fleshy, branching, 3f high, roughish. Leaves of a 
light green, large, irregularly cut into many deep and acute teeth. Flowers 
terminal, crowded, destitute of rays, white. Involucre large and tumid at base. 
Aug. Sept. 
58. XANTHIUM. 
Heads heterocephalous. Sterile——Involucre imbricate; anthers 
approximate, but distinct ; receptacle chaffy. Fertile—LInvolucre 2- 
leaved, clothed with hooked prickles, 1 or 2-beaked, 2-flowered ; sta- 
mens 0.—® Coarse weeds with alternate leaves. : 
1. X- Srrumarium. Clotweed. 
St. unarmed, pranching; lvs. cordate, lobed, 3-veined, unequally serrate, 
rough; fr. elliptical, armed with uncinate, stiff thorns, and ending with 2, spread- 
ing, straight horns.—A coarse, rough plant, in old fields, &c., N. Eng, and Mid. 
States. Stem branched, bristly, spotted, 2—3f high. Leaves large, on long 
stalks, rigid. Sterile flowers few together, terminal, globular, green. Fertile, in 
sessile, axillary tufts. Fruit a hard, 2-celled burr, near an inch long, covered 
with stiff, hooked prickles, which, like those of the common burdock, serve to 
disperse the seeds. Aug. §? 
2. X. ecuinAtum. Murray. (X. macrocarpon. DC. : 
St. rough and strigose, spotted; lvs. scabrous, obscurely lobed, obtuse, 
broad and subcordate at base, repand-toothed ; fr. oval, densely armed with ri- 
gid, uncinate bristles ; horns incurved.—A very coarse plant in marshes near 
the seacoast, Mass. to Car. Stem thick, 1—2fhigh. Fruit very large, hairy. 
Aug.—Oct. , 
3. X. spinosum. Prickly Clotweed, 
St. branched; spines at base of the leaves triple, slender; Jvs. ovate-lanceo- 
late, cuneate at base, petiolate, 3-lobed or dentate or entire, under surface and 
veins above whitish, twice longer than the spines; invol. oblong, with slender, 
uncinate spines.—Roadsides and fields, Mass, to Penn.! and Ga. Plant about 
1f high, very conspicuously armed with straw-colored spines }—1’ long. Heads 
sessile, sterile in the upper, fertile in the lower axils. Sept—Nov. — 
