

COM POSIT /E. Aster. 



§ 1. Biennials, rardy annuals or perennials, with leaves disposed to be incised or j'in- 

 natijid: scales of the involucre with green tips : rai/s sometimes sterile : akenes 

 with Strom/ vutn/iiial rihs and some slender nerves on both faces. (Involucre 

 covimonly resemblinii that of Corethro(jyne.) — ^iKCivM\i\mn\^iX\. {Madu^- 

 ranthern, Nccs. Dieteria, Nutt.) 



* Rays stylij'erous, but sometimes infertile. 



1. A. tanacetifolius, IIBK. Biennial or annual, pubescent and somewhat 

 viscid, a loot or less hiyli : leaves once to thrice pinnatilid, the lobes small and nar- 

 row : heads large, loosely corymbose : scales of the hemispherical involucre linear 

 and with spreailing herbaceous tips : rays 20 or more, violet : akenes villous. — 

 Machtkranthera tanacctifolia, Nees ; Hook. Bot. Mag. t. 4G24. Dieteria coronopi- 

 folia, Nutt. in Trans. Am. Phil. Soc. n. ser. vii. 301. 



S. E. Cahforuia, on the east sule of Providence Mountains, Dr. Cooper; thence through Ari- 

 zona to Colorado, east of tlie Uocky Mountains, and into Mexico. 



A. (MACii.KitANTiiKKA) I'AuviFLouiTS, Cray, which occurs on the Gila in Arizona, and may l>e 

 found within the State, is sniootiicr and much smaller. 



2. A. incanus, Gray, lloary with a line and close soft pubescence, slightly if 

 at all viscid, a foot or two high, loosely branched : leaves linear or narrowly lanceo- 

 late, entire, or some with a few lateral teeth, acute (an inch or so in length, abtuit 

 2 lines wide) : heads .solitary tcrnanuting the branches, largo : scules of the hemi- 

 spherical involucre linear-lanceolate, with long and squarrosu-spreuding or rellexed 

 foliaceous tips : rays 30 or nu)re, violet : akenes canescent. — Diplopappus in- 

 canus, Lindl. Bot. Keg. t. 1693 ; Hook. Bot. Mag. t. 3382. Dieteria incana, Torr. 

 & Gray, Fl. ii. 100. 



California, raised in England from seed collected by Douglas; the station unknown. Speci- 

 mens which accord with it were gathered in Guadalupe CaBon, Sonora, by Capt. E. K. Smith. 

 Head over half an incli in diameter across the disk : rays two thirds of an inch long. 



3. A. canescens, Pursh. Biennial, minutely puberulent-hoary or often green, 

 afoot or so in height: stems rigid, corymbosely or paniculately branched above : 

 leaves varying from ol.long-lanceolato or the lowest spatulate to linear, incisely or 

 almost spinufosely toothed, or sometimes entire, those of the llowering branches 

 reduced to subulate biacts : heads few or numerous, solitary, or mostly corymbose 

 or panicled : scales of the campanulate or obconical involucre rigid, appressed, 

 with short more or less squarrose-spreading green tips, the outer successively 

 shorter : rays 20 to 30, violet or bluish-purple : akenes canescently-pubescent. — 

 A. biennis, Nutt. Gen. ii. liiS. Dieteria canescens, pnlverulenta, divaricata, vi.wisa, 

 & sessilijiora, Nutt. in 'I'rans. Am. Phil. Soc. 1. c. Macharanthera canescens, Gray, 

 1. c. ; Eaton in l5ot. King. 



Dry regions, in the mountains behind San Diego and on the eastern slope of the Sierra Nevada 

 (Mono and Tahoe Lakes, &c.), extending north to the British boundary, and east to the eastern 

 base of the Rocky Mountains : a characteristic and most variable species ol tlie region. Heads 

 in the larger forms half an inch in diameter, and the rays half an inch long ; m others barely halt 

 that size, and the flowers much fewer. It is useless to distinguish particular varieties. Only low 

 and small-headed forms have as yet been found in California. 



^< * Rays completely neutral. — Hespekastrum, Gray. 



4. A. Shastensis, (Jray. Dwarf from a perennial rootstock, branclied and 

 tufted from the base, a span high, puberulentdioary : leaves small, spatulate or ob- 

 long, entire : heads solitary terminating the branches, small: scales of the campanu- 

 late involucre lanceolate, somewhat hoary and viscid, the outer with loose green 

 tips, the inner nearly destitute of lierbaceous tips : rays 15 to 20, rose-violet. — 

 Macharanthera (Hesjjerastrum) <f:)hastensis, Gray, Proc. Am. Acad. vi. 53U. 



On Mount Shasta, at about 9,000 feet. Brewer. Resembles a dwarf state of the last. Involu- 

 cre 4 lines long : rays 3 lines. 



