OF WESTERN SOUTn AMERICA. 151 



locality f artlier south than the neighbourhood of Lima. Bentham 

 (Trans. Linn. Soc. xxx. p. 378) has expressed a doubt whether 

 this is more than a local variety of the wide-spread and eminently 

 variable species Frosopis jitliflora, S\v. In the paper quoted, 

 containing his final views on the classification of this most 

 diflScnlt group of Ilimosece, Bentliam has united to P. julijlora 

 not less than 17 species of Prosopis described by various 

 authors. 



H 



Willd. This and the nearly allied A. macra- 



AcACiA ? A slender spiny bush without flower or fruit, 



so that the species, and even the genus, remain uncertain. 



Encelia canescexs, Cay., var. parvieolia. Having observed 



specimens of EnceJia growing at numerous stations on the 



west coast of South America, I have no hesitation in asserting 



my belief that they were all forms of the same species, and 



that the form growing at Payta, which is E, parvifolia^ H. B. K., 



as well as E, ohlongifolia, DC. Prod., should be united to the 



original species of Cavanilles, it being difficult to fix their limits 



even as varieties. I venture to doubt whether Asa Gray^s 



Californian species Tl, farinom^o^A^ not also be united to the 

 older species. 



CoLDExiA BiCHOTOMA, LeJim, A variable species, having a 

 wide range on the drier portions of the western side of 

 America, from the Tropic of Capricorn to Mexico. It has been 

 erroneously described as an annual, as it has a woody rootstock. 

 We are indebted to Asa Gray for uniting under the Linnean 

 genus CoJdenia, founded on a plant which extends through 

 -Africa and tropical Asia to the Philippines and Northern 

 Australia, a number of allied American plants which had been 

 ranted under five diff^erent generic names. Several of these are 

 strikingly alike in appearance, yet exhibit great differences In 

 the structure of the fruit. In regard to this I may express a 

 suspicion, founded on the imperfect examination of several 

 specimens, that in this group carpological differences such aa 

 usually mark generic distinction, may be found within the limits 

 of the same species. 



Galvesta ltmensts, Juss.y var. gka^ndifloea, Benth. in DC. 

 Prod. X. p. 296. Found flowering in some abundance in the 



