FLORA OF ST. CRO1X AND THE VIRGIN ISLANDS. 13 



munis j Datura Hetel and Stramonium, Euphorbia pilulif era, heterophyUa, 

 and JiypericifoUa, Mirabilis jalapa, Jatropha curc<'.$ 7 Cassia occidentalis, 

 and especially several kinds of Sida and Abutilon as well as some other 

 Malvaceae. 



The four formations mentioned above are usually found only on the 

 larger islands, the smaller ones, from their limited size, generally pos- 

 sessing chiefly the littoral and shrubby only. The island of Anegada, 

 although being one of the larger ones, yet from its structure and the 

 nature of its soil, seems to be chiefly covered by a vegetation composed 

 of the plants of the sandy shore, besides some of the trees and shrubs 

 following the settlement of man in these regions. Sir E. Schomburgk, 

 who has given a description of the island in the Journal of the Eoyal 

 Geographical Society, 1832, asserts that the island possesses several in- 

 teresting species of plants, among others a peculiar kind of Croton. As, 

 however, I have not been able to procure the work referred to above, I 

 am not prepared to say which those species are, and they are not men- 

 tioned by Prof. Grisebach in his Flora of the British West India Islands. 



Although, as stated above, the general character of the flora both in 

 St. Croix and the Virgin Islands, considered as a whole, is essentially 

 the same and distinctly West Indian, yet, in looking more closely into 

 details, we are soon struck by finding a great many species in the one 

 which are not found in the other. This is the more remarkable, as 

 from a geographical and climatical point of view the physical condi- 

 tions must be said to be materially identical. 



In referring to the list of plants given at the end of my treatise it will 

 be seen that out of a number of 881 indigenous phanerogamous species 

 no less than 215, or c. , are found in the Virgin Islands only, whilst 08, 

 or about , occur only in St. Croix, thus leaving only 568, or less than 

 |, in common to both. 



As may be expected from the general character of littoral vegetation, 

 there are very few species which are not found on both sides of the deep 

 channel separating St. Croix from its northern neighbours, the principal 

 exception being Baccliaris dioica, which only occurs in St. Croix, and 

 Eyletcs Domingensis, found by me only in the Virgin Islands. 



Some greater difference is found in the dry shrubby formation, where 

 several very common plants, such as Euphorbia petiolaris, Acacia sar- 

 mcntosa, Mamillaria nivosa, and others, are to be seen in the Virgin Isl- 

 ands only, St. Croix having to itself a few less common species, such as 

 Sccurhiega acidothamnus and Castela crecta. 



