54 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



the base; radical leaves orbicular to ovate, % to Y^ o^ an inch long, 

 more or less abruptly passing into slender petioles ^ to i inch long, 

 tomentose-wooly on both sides; upper cauline bracts opposite, connate, 

 setaceous recurved and uncinate ; involucres single in the forks, some- 

 what crowded along the short jointed intricate branches, tube narrowly 

 obconic, smooth, inconspicuously costate, and strongly corrugated; 

 divisions 3, more or less unequal, with prominent mid-rib and marginal 

 nerves, with few cross-veinlets, tomentose internally above the throat, 

 divergent, recurved and uncinate awned, a little longer than the tube, 

 flowers included, pedicellate, perianth cleft one-third; segments equal, 

 narrowly spathulate, with a small ciliate tuft near the summit; stamens 

 6, filaments unequal, inserted on the tube, anthers small orbicular; 

 akene oblong triangular; embryo with linear cotyledons, longer than 

 the slender radicle. 



Habitat: Dry, gravelly washes on the Colorado desert, March and 

 April. 



8. C. Watsoni, Torr. & (iray, Watson, Bot. King Exp., t. 34. Shortly 

 erect or decumbent, 2-4 inches high, appressed-pubescent, branching 

 at the base; radical leaves narrowly oblanceolate, tomentose beneath, 

 becoming revolute, lower cauline leaves similar but smaller, and unci- 

 nately awned, passing above into opposite recurved uncinate bracts; 

 involucres cymosely clustered on the u])per and terminal branches, tube 

 narrow, inconspicuously costate and corrugated, divisions 5, unequal, 

 one larger, three or four times exceeding the others, all shortly uncinate ; 

 flowers pedicellate, partly exsert, yellowish; perianth segments oblong, 

 acute, pubescent externally; stamens 9, on" the throat, with short fila- 

 ments, and small oval anthers; styles short, recurved; akene oblong- 

 triangular; embryo with linear cotyledons, as long as the radicle. 



Habitat : Desert districts of Nevada, and the Mojave. 



9. C. Orcuttiana, n. sp. Decumbent, 2-6 inches broad, appressed- 

 pubescent tliroughout, densely branched from the base ; radical leaves 

 narrowly lanceolate, obtuse, tapering to a slender petiole; cauline 

 leaves smaller, sessile, opposite, connate, obtuse; u])per involucral 

 bracts broadl)' triangular, scarious, accuminate ; involucres in the lower 

 forks and loosely scattered on the slender branches, sharply triangular, 

 with short chartaceous tube (not corrugated) ; divisions 3, nearly ecjual, 

 not conspicuously foliaceous, broadly divergent, with recurved uncinate 

 awns ; flowers partly exsert, pedicellate ; perianth as long as the pedi- 

 cel, tube narrowly turbinate, segments etjual, narrowly spathulate, with 



