158 COMPOSITE. (COMPOSITE FAMILY.) 



uppermost around the sessile (^ inch) heads and seldom surpassing them : invo- 

 lucral bracts more obtuse : pappus of the ray from ^ to -|^ the length of that 

 of the disk. — Mountains of Wyoming to Utah and Nevada. 

 ++■!-(• ++ Heads about J ijich long : sessile among the rosulate leaves : herhaqe 

 soft-Ianate : pappus deciduous in a ring. 



10. T. spathulata, Xutt. Depressed and raulticipital, forming a tuft an 

 inch or so higli : leaves crowded, spatulate, densely villous-lanate ; the upper 

 about equalling the heads : bracts of the involucre oblong-lanceolate, acute : 

 rays rather short, pinkish : pappus of ray and disk similar, of slender bristles. 

 — Mountains of Wyoming. 



++++++ +H- Heads small, i inch high {exclusive of the rays), mostly short-pedun- 

 culate : involucre of broadly lanceolate and barely acute bracts : caulescent 

 and branching : pappus of the ray shorter, commonly of chaffy bristles. 

 = Green and glabrate. 



11. T. glabella, Gray. An inch or two high, nearly simple, spnrsely 

 pilose-pubescent when young : leaves thickish, soon glabrous, spatulate, an 

 inch or less long, including the usually slender petiole ; the uppermostiisually 

 surpassed by the slender and naked peduncle : involucre glabrous. — Proc. 

 Am. Acad. xvi. 86. S. W. Colorado, Newberry. 



= = Cinereous with fine and close pubescence, flowering from near the ground at 

 first, but becoming taller (4 to 10 inches high) and loosely branching. 



12. T. Fendleri, Gray. Leaves linear : bracts of the involucre unequal, 

 in about 3 ranJcs, acute. — PI. Fendl. 70. Xew Mexico and S. Colorado. 



13. T. strigosa, Nutt. Flowering when only i inch high, often attain- 

 ing a span in height : early leaves spatulate ; later ones linear : heads rather 

 smaller : bracts of the involucre broader, acutish, in about 2 ranks, the outer 

 shorter. — Wyoming to New ^Mexico and Arizona. 



13. ASTER, Tourn. Starwoet. Aster. 



The largest and by far the most difficult of our genera, not naturally sepa- 

 rated from Eriqeron. All are herbs, mostly perennial, and especially charac- 

 teristic of North America. Includes Machceranthera and Diplopappus. 



§ 1. Involucral bracts {at least the outer ones) iclth green herbaceous tips or 

 appendages, or irholly or partly foliaceous, imbricated or many-ranked, their 

 margins not scarious : akenes from obovate-ohlong to linear, 3 to several- 

 nerved: pappus rather fine and soft {in one or two species more coarse and 

 rigid), simple {with no exterior series). — Aster proper. 

 * Involucre well imbricated : the bracts appressed and coriaceous, with more or 

 less spreading herbaceous tips: akenes narroiv, 5 to lO-nerved : pappus more 

 rigid than in the following groups: rays showy, blue or violet: leaves firm, 

 acutely serrate, more or less scabrous, none of them, cordate or clasping ; the 

 radical tapering at base into margined petioles. 



1. A. Sibiricus, L. A span to afoot high, somewhat cinereous-pubescent 

 or puberulcDt, or the foliage scabrous : heads solitary, terminating the stem 

 or corymbiform branches : leaves oblong-spatulate to broadly lanceolate, 1 to 

 3 inches long : involucre 3 lines high, shorter than the disk ; its bracts narrowly 



