OF ARTS AND SCIENCES. 195 



poses to transfer from Perityle the species which have subulate instead 

 of linear style-appendages. But this separates plants of wholly similar 

 aspect and structure, and would bring into Perityle tlie Lnphamia dissecta, 

 which has short and obtuse style-appendages. I do not find that the 

 involucral scales are to any extent or with any uniformity wrapped 

 around the outermost akenes. Perityle Emoryi and P. nuda (forms 

 of one species), although referred by Bentham to Laphamia, have short 

 and obtuse style-appendages in our specimens ; but a plant which I 

 cannot otherwise at all distinguish, collected on Carmen Island, in 

 Lower California, by Dr. E. Palmer, in 1870, has them subulate and 

 acute. As to the character " receptaculum convexum vel conicum," 

 the receptacle was described and figured as flat in the original 

 Perityle : in fact it is barely convex in some species, but strongly so 

 in others. 



Whitneya Gray. Since this genus was characterized, from scanty 

 specimens, I have myself collected the plant, and have received from 

 Drs. Bolander and Kellogg specimens with well-formed fruit. Upon 

 these materials the genus is newly characterized for the Flora of Cali- 

 fornia. The principal points of emendation are these: 1. The ligules 

 become papery, almost as much so as in a Zinnia, and persist on the 

 achenium, with which they are articulated indeed, but from which they 

 are not readily separated : the 10 to 16 nerves are prominently decur- 

 rent down on the short tube of the ray. 2. The ovaries of the disk are 

 all sterile, although the style-branches bear obvious stigmatic lines ; and 

 the disk-corollas appear equally to persist on the sterile achenia. 3. 

 The rays mostly bear sterile filaments. 4. I do not verify Bentham's 

 character of the inclusion of the ray-achenia in the scales of the invo- 

 lucre. They are concave close to the base, indeed, but not at all so as 

 to embrace the achenium. The genus may be associated with 



RiDDELLiA Nutt. The Zinnia-like persistence of the rays is not 

 noted in the Genera Plantarum, except by the phrase " lamina rigi- 

 dula." The rays do become more rigid than in 



Baileta Gray. In tliis the persistent scarious rays want the tube, 

 as is mostly the case in Zinnia. The affinity of these three genera (i.e. 

 of Riddellia, Baileya, and Whitneya) now becomes manifest. They 

 form a group in the Helenioidece analogous to that of the Zinnece in 

 HelianthoidecB. In the Floi'a of California, now in preparation, I have 

 accordingly formed of them the subtribe Riddellie^. 



BjERIA and Bdrkielia. If the two genera are kept up in the 

 manner proposed by Mr. Bentham, as seems on the whole advisable, 

 the stress of the character of the latter should come rather upon the 



