196 University of California Publications in Botany. [VOL. 3 



Copeland, Miss Warner, no. 26) ; (d) central achenes with 4 to 6 

 slender paleae about as long as corolla (Hall, no. 3032, and paleae 

 sometimes 5 in Davy, no. 1891) ; (e) all the achenes with 1 long 

 acute palea and 3 short ones, the latter of varying lengths and 

 attenuate to obtuse (Hall, no. 2807a). It is a common occurrence 

 for the flowers of the second circle from the involucre to have 

 paleae of several different lengths on a single achene. Since such 

 numerous variations as those enumerated above are found in 

 plants growing near together, and even within single heads of 

 some plants, pappus characters can be of no value in separating 

 species of this group. It should be noted, however, that an outer 

 series of paleae occurs only in C. Xantiana and C. macrantha. 

 two species also well marked by other characters. 



5. C. Xantiana Gray, Proc. Am. Acad. vi. 545 (1865) ; Hall, 

 Bot. Gaz. xxxi. 391 (1901). C. Xantiana integrifolia Gray, Bot. 

 Calif, i. 390 (1876). 



A stout and somewhat fistulous-stemmed annual, 1.5 to 3 dm. 

 high: herbage early glabrate, except on the involucres and pe- 

 duncles, which commonly retain a slight woolliness : largest leaves 

 4 to 8 or 10 cm. long, all linear and entire or usually once-parted 

 into similar lobes: heads scattered on stout commonly fistulous 

 peduncles: involucral bracts extremely variable, sometimes 

 shorter than the disk, often with spreading obtuse foliaceous tips 

 much exceeding the disk, traversed by 1 strong nerve and several 

 obscure ones: flowers white or flesh-colored, the marginal ones 

 scarcely enlarged : inner paleae of the pappus as long as or longer 

 than the flowers; outer paleae conspicuous, obtuse, as broad as 

 long. 



Common in and around Antelope Valley from the Mohave 

 River to Mt. Pinos, Ventura Co., and Fort Tejon, Kern Co., as- 

 cending the mountains to 2200 m. ; north along the eastern base 

 of the Sierra Nevadas to Oregon. This species and C. Fremonti 

 are much alike in general appearance and exhibit similar ecolog- 

 ical variations but differ in pubescence, in the pappus, and in 

 the involucre, the bracts of which have a strong tendency to end 

 in foliaceous tips in C. Xantiana, In alkaline soil the plants be- 

 come more robust and succulent, and the involucral bracts and 

 pappus much elongated. 



