400 COMPOSITAE LYGODESMIA 



AGOSERIS 



Receptacle flat, naked. Achenes terete, obscurely striate or an- 

 gled, usually linear or slender-fusiform. Pappus of copious and 

 usually unequal soft or somewhat rigid bristles, from white to 

 brownish. 



L. juncea Don 1. c. Perennial by a thick woody root: stems .stiff, 

 much branched, 8-18 inches high, striate-angled, not spinescent : lower 

 leaves lanceolate, rigid, entire, acute or acuminate, %-2 inches long; the 

 upper similar but smaller, or reduced to subulate scales : heads mostly 

 5-flowered, solitary at the ends of the branches: involucre about half -inch 

 high, its bracts usually gland-tipped: achenes narrowly tolumnar or 

 shortly tapering to the summit : pappus light brown. Dry plains, eastern 

 Idaho to Nevada and Minnesota. 



L. spinosa Nutt. Trans. Am. Phil. Soc. vii, 444. Stems slender and 

 rigid, low, much branched from an indurated and matted-woolly peren- 

 nial base, otherwise glabrous ; branchlets divergent, spinescent, bearing 

 minute scales in place of leaves, and lateral very short-peduncled heads : 

 lower cauline leaves linear,, entire, thickish, above soon reduced to scales: 

 involucre 3-5-flowered ; its principal bracts not more numerous, rather 

 loose, lanceolate; the vmequal and more imbiicated calyculate ones com- 

 paratively broad and large: achenes much shorter than the pappus, not at 

 all narrowed upward, 4-5-costate : pappus white, of unequal bristles. 

 Gravelly hills and plains, eastern Oregon to California, Nevada and Idaho. 



109 AGOSERIS Raf. Fl. Loudv. 58. 

 TROXIMON Nuttall, not of Gacrtner. 



Acaulescent perennial or annual herbs with clustered radical 

 leaves and mostly large heads of yellow flowers on simple scapes. 

 Involucre campanulate or cylindraceous, the bracts mostly lan- 

 ceolate, imbricated in few series, the outer loose and often some- 

 what foliaceous. Receptacle flat, naked. Achenes oblong or 

 linear, terete, 10-ribbed, the apex contracted into a neck or pro- 

 longed into a beak, the broad base or basal callus to a narrow 

 base more or less hollowed at the insertion. Pappus of copious 

 white or whitish merely scabrous capillary bristles, which are 

 either persistent on or separately deciduous from the dilated 

 terminal areola. 



§ 1 Achenes more or less linear, beakless, or tapering gradually into 

 a beak on which the nerves or ribs of the body are produced to the 

 apex ; acaulescent perennials. 



* No beak to the achene, its moderately short continued summit of 

 the same texture as the body and equally 10-costate : involucral bracts 

 somewhat equal, all tapering to a slender acumination : the outer from 

 an oblong or ovate-lanceolate base, glabrous : pappus rig'dulous. 



A. alpestris Greene Pitt, ii, 177. Troximon alpestre Gray. Glabrous: 

 rootstock or caudex elongated ; leaves narrowly spatulate or lanceolate, 

 pinnately lobed or incised, or parted into narrow linear divisions : scapes 

 2-3 inches high, weak: involucre campanulate, 7-8 lines high, the bracts 

 in about 3 series : achenes 2-3 lines long, equalled by the slender pappus- 

 bristles. In the Cascade Mountains of Oregon and Washington, 



* * Achenes with apex tapering gradually into a rather stout and 

 nerved beak which is shorter than the body. 



