PLANT>E NOV^ THURBERIAN^T.. 323 



dunculis alaribus gracilibus monocephalis ; involucri squamis oblongo-lanccolatis acu- 

 tatis baud striatis. — On the Californian desert near the Rio Colorado (along with 

 Eremiastrum), February, 1852. — Tlio specimen (which is just beginning to flower) 

 evidently indicates a third species of Psathyrotes, of nearly the habit of P. amma. The 

 plant is clothed with thicker and longer wool (which appears to be deciduous with 

 age) ; the cuneate leaves are deeply and sharply incised ; the naked peduncles acquire 

 the length of 1 ^ or 2 inches, and bear a larger head than that of P. annua ; the pap- 

 pus, as in that species, is not much shorter than the corolla, the lobes of which arc 

 similarly, but less strongly, glandular-villous outside. — P. annua was also found by 

 Mr. Thurber, at Big-IIorn Mountain on the Gila, June, 18.52; in this region (and not 

 properly in New Mexico) Mr. Gambell probably gathered the specimen described by 

 Nuttall. Dr. Torrcy also informs me that the plant was gathered by Colonel Emory, 

 in his first exploration, and that it is his Tctradijtnia [Polijdi/mia) ramosissima, described 

 in Emory's Report, p. 14.5, where it is suggested as the probable type of a new genus. 

 Had I been aware of the fact, I should probably have adopted for the genus the name 

 suggested by Dr. Torrey, who had rightly indicated the affinities of the plant, and 

 whose description was published in the same year with that of Mr. Nuttall. Mr. Tliur- 

 ber notes that the flowers of P. annua are not ochroleucous, but hri/jht i/ellow, and the 

 leaves are aromatic. 



BARTLETTIA, Nov. Gen. Compositaruni. 



Capitulum multiflorum, heterogamum, radiatnm ; ligulis uniseriatis fa'mineis. In- 

 volucrum subtriseriale, campanulatum ; squamis oblongo-lanccolatis, exterioribus mi- 

 noribus. Receptaculum convexo-conicum, tuberculato-alvcolatum. Corollas tubo gra- 

 cillimo subpiloso ; disci fauce infundibuliformi, limbo 5-lobo ; ligulac oblonga;. Styli 

 rami graciles, plani, la;vi, fl. disci apice capitellato-truncato tantum puberuli, radii se- 

 tula apiculati. Achenia (valde juniora) radii et disci conformia, oblonga, compressa, 

 raarginibus uninervatis longe ciliata. Pappus uniserialis, e setis capillaribus circiter 

 20 tenuibus sed rigidulis dcntato-barbellulatis corolla disci brevioribus. — irerba an- 

 nua, parvula, glabella ; foliis in caule brevissimo plerisque alternis longe pctiolatis ro- 

 tundatis denticulatis sa^pe trilobis ; pedunculis scapiformibus (spithamajis) monocepha- 

 lis ; floribus flavis. 



Bartlettia scaposa. — On a prairie, near Corralitas, Chihuahua, August, 18;'52. — 

 Leaves sparsely hirsute, but soon glabrate ; the petioles an inch long : the blade only 



