444 Order 70.— COMPOSITE. 



4 A. bidentata Ms. Very hirsute ; si branching ; branches simple ; lvs. crowded 

 mostly alternate, closely sessile or partly clasping, undivided, oblong, with a single 

 tooth or short lobe on each side near the base ; sterile hds. densely spicate, fer- 

 tile axillary; jr. ^-angled, acutely pointed, the 4 ribs produced in 4 short spineai 

 — (T) Prairies, 111. to La. Stem 1 — 3f high, with numerous leaves and very dense, 

 terminal spikes. Jl. — Sept. 



46. XAN'THIUM, Town. Clot-weed. Heads heterocephalous. 

 Sterile, in globous heads ; scales distinct, in one row ; anthers approxi- 

 mate, but distinct; receptacle chaffy. Fertile: involucre 2-leavcd, 

 clothed with hooked prickles, 1 or 2-beaked, enclosing 2 flowers; 

 stamens 0. — (D Coarse weeds with alternate lvs. 



1 X. Strumarium L. Hough, unarmed, branching; lvs. cordate, lobed, 3-veined, 

 unequally serrate ; fr. elliptical, armed with uncinate, stiff thorns, and ending 

 with 2, spreading, straight horns. — A. coarse, rough plant, in old nelds, &c. N. 

 Eng. and Mid. States. Stem branched, bristly, spotted, 2 — 3f high. Leaves 

 large, on long stalks, rigid. £ Fls. few together, terminal, globular, green ; 5 

 in sessile, axillary tufts. Fruit a hard, 2-celled burr, near an inch long, covered 

 with stiff, hooked prickles, which, like those of tho common burdock, serve to 

 disperse the seeds. Aug. — Variable; fruit more than 1', or less than 1' in length; 

 thorns very close or somewhat scattered ; horns spreading or incurved. (X. 

 cchinatum Murray.) 



2 X. spinosum L. Wliiiish-downy, armed with triple, slender, subaxillary spines, 

 spines at base of the leaves triple, slender ; lvs. ovate-lanceolate, cuneate at base, 

 pctiolate, 3-lobed or dentate or entire, under surface and veins above whitish, 

 twice longer than tho spines ; invol. oblong, with slender, uncinate thorns. — 

 Roadsides and fields, Mass. to Penn. and Ga. Plant about If high, very con- 

 spicuously armed with straw-colored spines \ — 1' long. Heads sessile, sterile in 

 the upper, fertile in the lower axils. Sept. — Nov. 



47. RELANTHERA, Cass. (Gr. ftiXag, black, Lat. arJkcra, an- 

 ther.) Heads discoid ; flowers all tabular, g ; scales in 2 subequal 

 scries ; receptacle chaffy, the pales partly investing the flowers ; 

 achenia short, truncate, angular ; pappus a few minute caducous awns 

 or bristles. — 21 Herbs rough, with square stems, opposite, pctioled, 3- 

 vcined lvs. and long pcduncled hds. Cor. white. Anth. black, tip- 

 ped with a white appendage. 



M. hastata Mx. Lvs. hastately 3-lobed, acuminate, dentate, on slender petioles; 

 scales ovate-lanceolate, acuminate, pales rigid, cusp-pointed. — Dry soils, S. Car 

 to Pla and La. Sts. 3 to Cf high, beautifully variegated with purple, the branches 

 elender, erect, few-flowered. Lvs. deep green, very rough, 4 to 6' long, the 

 upper smaller. Hdd. near G" broad, of stiff scales and singularly contrasted, 

 colors. — Jl. — Sept 



48. ZIN'NIA, L. (To John Godfrey Zinn, a German botanist, 

 1557.) Heads radiate ; rays $, disk tubular, £ '» scales of the involucre 

 oval, margined, imbricate ; receptacle chafl'y, conical ; pappus of the 

 disk of 1 or 2 erect, flat awns. — Q American herbs, with apposite, 

 entire lvs. and solitary terminal hds. Rays bright colored, showy. 



Z. multifldra L. Lvs. ovate-lanceolate, abrupt at base, scarcely petioled; hds. 

 on peduncles as long as the lvs. ; pales obtuse, entire ; ach. of the disk with one 

 awn. — Fields and waysides, Ga., Fla., to Tex. Sts. C to 2f high, simple or 

 nearly so. Lvs. 1 to 2' long, rather obtuse. Ped. enlarged upwards, hollow 

 Eajs about 12, oval, scarlet within, yellowish without. May, Jn. § 



2 Z. elegans L. Lvs. ovate, cordate, sessile-amplexicaul ; hds. on ped. 

 longer than the lvs. ; pales serrated; ach. of the disk with 2 awns. — Gardens; 

 Plant tall, elegant and showy, with brilliant fls. of varying colors, as orange, 

 scarlet, crimson, purple, violet and white. JL, Aug. f Mexico. 



