Flora of central France. 67 



the centre presents, compared with those of meridional de- 

 partments of France. It is necessary also to remark the 

 affinities of the central region with the north, the east, and 

 the west of France. It is particularly from the west that the 

 Flora of the centre draws its most characteristic feature. 



The author thinks that the plants of the west are propa- 

 gated even to the centre of France by passing up the vallies 

 of the Loire, and more especially those of the Cher and 

 l'lndre. 



Perhaps also the marine atmosphere exercises its influence 

 as far as the occidental part of the central region ; at least 

 it is to this influence, more than the elevation of temperature, 

 that we must attribute the complete development of certain 

 vegetables which in the central part support the winter's 

 cold with great difficulty ; for example, it is only in the west 

 of the departments of l'lndre, and of Loire-et-Cher that 

 the Cerasus (Lauro Cerasus) and the Laurus nobilis bear 

 fruit, and are reproduced spontaneously from seed ; it is 

 there only that the Punica granatum ripens its fruit, and 

 braves the most rigorous winters. 



M. Boreau has determined the limits which certain plants 

 of the west respect with regard to those of the central 

 region. The Erica ciliaris does not appear to advance far- 

 ther than de Blois ; the Erica scoparia, which is found at the 

 north of the forest of Orleans and at Fontainbleau, does not 

 pass to the east of the Loire ; it encroaches little on the limits 

 of Sologne and of the department of l'lndre, and is not 

 found in the department of Nievre : it is the same for the 

 Pinguicula lusitanica, Helianthemum alyssoides, Quercus 

 toza, and of many others which pass as far as Bourges, but 

 few of which pass the department of Cher. 



A Flora which draws all its characteristic traits from 

 contiguous regions can not exhibit plants so very peculiar 

 that they cannot be met with in many other localities. How- 

 ever the Euphrasia jaubertiana has only been found in 



