178 COMPOSITES. (COMPOSITE FAMILY.) 



or sometimes thinly floccose, the short decurrent bases or adnate auricles rather 

 broad, slightly if at all glandular or heavy-scented: heads in single or few close 

 glomerules terminating the stem or branches : involucre hemispherical, white 

 or yellowish, becoming rusty -tinged. G. luteo-album, var. Sprengelii, Eaton. 

 From Texas and Colorado to S. California and N. Oregon. 



2. G. decurrens, Ives. Stem stout, 2 or 3 feet high, corymbosely 

 branched above and bearing cymosely crowded glomerules of broad heads : leaves 

 very numerous, lanceolate or the upper linear, obviously adnate-decurrent, the 

 upper face becoming naked and green in age and with the stem glandular-pubes- 

 cent or viscid, white-woolly beneath, strongly balsamic-scented: involucre cam- 

 panulate, white, becoming rusty-tinged. Am. Jour. Sci. i. 380. From Texas 

 and New Mexico to Washington Territory and British Columbia, and eastward 

 to New England. 



# * Involucre less imbricated, more involved in wool, the scarious tips of the nearly 

 equal bracts inconspicuous and dull-colored: heads glomerate and feafy-bracte- 

 ate, only a line or so in length : low and branching annuals, a few inches or 

 rarely a foot high : akenes either smooth or scabrous. 



3. G. paluatre, Nutt. Loosely floccose with long wool, erect, at length 

 diffuse or weak : leaves 3 to 5 lines wide, spatulate or the uppermost oblong or 

 lanceolate : tips of the linear involucral bracts white, obtuse. In moist 

 grounds from New Mexico to Wyoming and westward. 



4. G. strictum, Gray. Appressed-woolly : stem strict and simple, a span 

 to a foot high, sometimes branching or with ascending stems from the base : 

 leaves all linear, seldom a line wide : heads in spicately disposed glomerules in 

 the axils or on short lateral branches : involucral bracts with brownish or some- 

 what whitish tips, obtuse. Pacif. R. Rep. iv. 110. Rocky Mountain region, 

 from Wyoming to New Mexico and Arizona. 



21. MELAMPODIUM, L. 



Branching herbs, with opposite mostly sessile leaves, and pedunculate heads 

 terminating the branches or in the forks. In our species the rays are con- 

 spicuously exserted and white, and the fructiferous bracts hooded. 



1. M. cinereum, DC. Branched from the base, a span to a foot high, 

 cinereous or even silvery-canescent with a close pubescence, or greener : leaves 

 linear or the lower lanceolate or spatulate, entire or undulate, or even sinuate- 

 pinnatifid: ligules 5 to 9, cuneate-oblong, 2 to 3-lobed at apex, 3 to 6 lines 

 long : bracts of the involucre ovate, appressed, slightly united at base : fruc- 

 tiferous bracts nearly terete, somewhat incurved, muricate with sharp tubercles ; 

 its hood about the length of the body and very much wider, nearly smooth, 

 its truncate and usually even margin commonly incurved. From S. and E. 

 Colorado to Arizona, Texas, and W. Arkansas. 



22. SILPHIUM, L. ROSIN-WEED. 



Tall and coarse perennials : with resinous juice, large leaves, and ample 

 pedunculate heads of yellow flowers. Our species is the " Compass-Plant," 

 with alternate deeply pinnatifld or bipinnatifid leaves, and large heads (sessile 

 or nearly so) racemosely disposed along the naked summit, and very rough 

 herbage. 



