AND GENERA OF PLANTS. 301 
Has, Arid plains towards the sources of the Platte. | Rays short, pale purple, obscurely toothed, 
almost entire. Nearly allied to the preceding. Scales of the involucrum about three series, acute. 
Dieteria * divaricata; pulverulently pubescent, radical leaves spathulate or 
lanceolate, repandly and incisely serrate, above smaller, linear, sessile and 
nearly entire; stem divaricate, branchlets subracemose, or one or two flowered, 
fastigiate; sepals about four series, reflected ; rays twelve to sixteen, about as 
long as the disk. 
Has. Denudated plains of the Rocky Mountains, and Oregon, common. Rays short, palé blue 
or purple. Pappus fulvous or white, (the white shorter and less copious, perhaps the mark of a 
different species ;) branches rather naked, with small leaves spreading out into a compound corymb. 
About a foot high. 
Dieteria * viscosa; pulverulently pubescent, and more or less glandular and 
_ viscid ; leaves all linear or lanceolate-linear, pinnatifidly or incisely serrate, acu- 
minate, uppermost entire, sessile; stems simple, racemosely and corymbosely 
branched; scales of the involucrum acute, reflected at the tips, imbricated 
closely and equally in about five series; rays eighteen to twenty, about as long 
as the disk. 
Has. With the above, particularly near Scott’s Bluff, on the Platte. Rays longer than in the 
preceding, purple. Stem simple, attenuated, often very viscid, and exhaling the strong, heavy 
scent of Aster graveolens or Gnaphalium Americanum. Scales of the involucrum very numerous, 
lanceolate, acute. Leaves sometimes nearly pinnatifid or runcinate. Pappus fulvous, that of the 
discal florets about thirty-five to forty unequal rays, that of the radial female florets much shorter. 
of about twenty-four rays. : 
Dieteria * sessiflora; viscidly pubescent; stem simple, flowers sessile, in ax- 
illary and terminal clusters; leaves linear or sublanceolate, incise or subpinna- 
tifid, acutely acuminate, sessile; sepals in about four series; rays ochroleucous, 
twelve to fifteen, about the length of the disk. 
Has. With the above. About a foot high, stem mostly unbranched, seales of the involucrum 
very glutinous. © Nearly allied to 2plopappus spinulosus, (Decanv.) to which I applied the name 
of Sideranthus in Fraser’s catalogue; that plant is, however, perennial. Closely allied to the pre- 
ceding species, but differing much in the pale yellow rays; the pappus of the rays is, also, nearly 
equal with that of the discal florets. Flowers smaller than in any of the preceding. 
+ t Root perennial. Flowers wholly yellow. (SteRantuvs.) 
Dieteria spinulosa. Aplopappus spinulosus. Decanp. Vol. V., p. 347. This spe- 
vil.—4 A 
