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ENUMERATION PROVISOIRE DES ESPÈCES 



DU 



Genre CERASTIUM 



Frédéric N. WILLIAMS 



It will be some time before the material, from various sources, for a 

 monograph of the genus Cerastium can be codified and arranged. As the 

 main lines of the grouping of species have been definitely worked out, 

 this list is put forward rather as a synoptic index in order to facilitate 

 the discrimination of spécimens, and with the examination of further 

 material may possibly be modified. The systematic revision of an invol- 

 ved genus is a slow process; the more so is this the case in a genus of 

 plants which have not enjoyed floricultural favors. Présent views on the 

 relative importance of the characters on which the primary and secon- 

 dary groups are based are, however, not likely to be impaired by 

 further repeated examination of spécimens. This, therefore, may be an 

 excuse for Publishing the list of species as a preliminary instalment. 



Species of Cerastium may generally be distinguished from those of 

 Stellaria and Arenaria by habit, although not always satisfactorily. At 

 the same time, if the fruit- characters of a typical Cerastium be kept in 

 view, there ought to be no difficulty in defining the genus or in circum- 

 scribing the species. As defined by Linnseus and aptly named by Dille- 

 nius it is characteristic enough. 



In the matter of habit and aspect Stellaria includes slender, diffuse, 

 glabrous herbs, while the species of Cerastium are pubescent, though 

 C. perfoliatum Linn. is a conspicuous exception, and the perennial forms 



