1907] Hall. Compositae of Southern California. 109 



extra-Californian species. Receptacle convex, not chaffy. In- 

 volucral bracts scarious, imbricated. Staminate flowers with 

 filiform corolla, entire or merely notched style, and a pappus of 

 rather scant bristles which are barbellate or plumose at the tip 

 and thus apparently thickened. Pistillate flowers with abundant 

 pappus of fine filiform bristles commonly united at base, and 

 falling away in a ring. 



Heads solitary, terminating short stems or sessile among the basal leaves: 



pappus-bristles of sterile flowers hardly thickened at apex 



1. A. dimorpha. 



Heads in cymose clusters terminating short or elongated stems: pappus- 

 bristles of sterile flowers with thick or dilated tips. 



Tips of involucral bracts green to pale brown 2. A. media. 



Tips of involucral bracts rose-pink or white. 



Leaves permanently hoary on both faces 3. A. speciosa. 



Leaves green above 4. A. marginata. 



1. A. dimorpha (Nutt.) T. & G., Fl. ii. 431 (1843). Gnapha- 

 lium dimorpJnim Nutt., Trans. Am. Philos. Soc. ser. 2, vii. 405 

 (1841). 



Depressed, cespitose, the stout caudex much branched and 

 bearing rosulate clusters of narrowly spatulate leaves which are 

 tomentose on both sides : heads solitary, subsessile at the crown 

 or terminating branches 4 cm. or less long : involucre of the 

 staminate heads about 6 mm. high, of the pistillate heads enlarg- 

 ing to 1 or 2 cm., the former with brownish or bluish obtuse 

 bracts, the latter with often paler bracts, the innermost of which 

 are narrow and attenuate into a hyaline tip. 



On dry stony slopes in the mountains : Bear Valley, San 

 Bernardino Mts., Parish; Lytle Creek, San Antonio Mts. ; sum- 

 mit of Mt. Pinos, Ventura Co. ; thence to British Columbia, 

 Montana, etc. 



2. A. media Greene, Pitt. iii. 286 (1898). 



Densely cespitose, 1 dm. or less (usually 4 or 5 cm.) high 

 including the flowering stems: herbage tomentose throughout: 

 leaves narrowly oblanceolate or spatulate, acute, .4 to .8 (rarely 

 1.2) cm. long: involucre about 4 mm. high; bracts obtuse, green 

 or greenish-brown with lighter tips, those of the pistillate heads 

 oblong or linear-oblong, of the staminate heads oval. 



