20 



PROCEEDINGS OF THE CALIFORNIA 



Description of a New Genus and Species of Plant from Ne- 

 vada Territory. 



BY A. KELLOGG, M.D. 



Pterostephanus Kellogg. 



Involucre obconically-corupanulate ; scales loosely imbricated in about two 

 to three series ; the exterior unequal, calyculate, suborbicular, oval, or oblong, 

 obtuse ; the inner series (of about eight) sub-equal, oblong-lanceolate, obtuse ; 

 scarious margins entire ; (a broad, diffusely green line marks the centre). Re- 

 ceptacle naked, alveolate, alveoli, toothed. Achenia (mature wanting), oblong, 

 sub-cuneate, or sub-obovate, somewhat compressed (?), slightly contracted at the 

 crown, smooth, sub-pubescent above, on a short stipe. Pappus double ; the 

 exterior coroniform, persistent — a hyaline erateriform cup, with an even but 

 minutely crenulate edge; interior of five (white) plumose, glabrous bristles, 

 gradually dilating towards the base. 



Californian herbs, with runcinately, pinnatifid, radical leaves, and numerous 

 naked scapes, bearing solitary, tigulate, yellow flowers ; closely allied to Mala- 

 cothrix and Calycoseris, but with a plumose pappus. 



Fig. 4. 



