REVIEWS AND CRITICISMS. 107 



The two orders, which most interest West American botanists are, 

 naturally, the Caryophyllacese and the Rhamnacese. In the genus 

 Ceanothus of the latter order thirty-six species are recognized, and 

 six varieties. Without doubt Dr. Trelease was wise in his rather 

 close limitation of the number of species, for continued exploration 

 will tend to decrease the number of species and increase the number 

 of varieties. Ceanothtis divergens, which now figures as a variety 

 of C. prostratus, seemed at one time a clear species. The range of 

 C. prostratus m the Coast mountains has been extended, during the 

 last summer, so far southward of the locality given in the Synoptical 

 Flora that the species is now known to join on to the variety not 

 only morphologically but, furthermore, geographically. The Coast 

 Ranges immediate to San Francisco Bay, particularly northward, 

 are wonderfully rich in Ceanothus forms, many natural varieties, 

 not well known or even named, seeming distinct species to the local 

 collector, are of both interest and importance, and for tliese, descrip- 

 tions will some day be prepared and given place. In this way the 

 necessary emphasis of the longitudinal and altitudinal variants can 

 be made. It is also to be hoped that field research will explain or 

 justify the curious range assigned to the plants called C. pinetoru7n, 

 i. <?., "Lake County to Taraalpais and Tulare County." 



The preparation of the Caryophyllacese, a most difficult order. 

 Dr. Robinson himself assumed. The soil- variations in this group 

 are especially numerous and perplexing; characters^ which are avail- 

 able to the systematist^ when dealing with plants from a restricted 

 area, disappear when the problem is the consideration of all avail- 

 able material. Hence inevitable reductions: Spergularia gracilis is 

 reduced to 6". Platensis of South America and similar things befall 

 elsewhere. The study of Silene and Lychnis has developed much 

 that is new and valuable. In this connection it is interesting to note 

 that Sile?ie imdtinervia, Wats., which most Californian botanists 

 believe to be an alien, is retained for the present as a native, the author 

 having been unable to refer it to any foreign species. Cerastiuni 

 pilosum, however, is definitely excluded from our State, the plant of 

 Point Reyes being now referred to C. arvense, var. maximum, 

 Britt. & Hollick. For twenty years the description of Bigelow's 

 Point Reyes specimen under the title of C. pilosum has been doubt- 

 fully copied from one local flora into another. 



