310 "APPENDIX TO THE 'SPICILEGIA GORGONEA.' 
In conjunction with so great a similarity in this insular vegetation, 
it is worth while to remark that scarcely a species of the Macaronesian 
Flora is found on the African continent opposite, or even to the north 
of, the Cape de Verd Islands, and one species only, the Laurocerasus 
Lusitanica, reaches the European continent in Portugal. The causes 
of this difference are probably not very remote ;—but this topic would 
lead us too far away from our present purpose. 
ANONACES, 
la. Anona muricata, Linn. This American species, of common 
occurrence in the West Indies, is found naturalized, according to 
M. Bocandé, in the island of Santiago. 
1 à. Anona Cherimolia, Mill. Likewise an American species, 
cultivated throughout the tropics, and as far north as Palermo, where 
it ripens its fruit. It is,as Mr. Bentham observes, perfectly naturalized 
in the Cape de Verd Islands, and occurs in our present collection. 
REsEDACEX. 
12. Caylusia canescens, St. Hil. Although our present collection 
adds nothing to this Order, yet a few remarks, in addition to what has 
already been said on Caylusia canescens, St. Hil, in regard to the 
peculiar conformation of its ovarium, will not be out of place here. 
This species is supposed to present the structure, very rare in itself, 
and anomalous in this tribe, of a free central placenta. Such is the 
conclusion to which a very able and ingenious observer, M. A. de St. 
Hilaire, has arrived (2ème Mém. sur les Resed. p. 28) ; and his opinion 
has been reproduced by Dr. Lindley and Endlicher, in their highly 
valuable works, the * Vegetable Kingdom’ and the * Genera Plantarum.’ 
I am, therefore, desirous of showing that this anomaly is rather 
apparent than real, and that the general conformation of the Order 
provides us with a different solution. : 
The placenta, evidently parietal in the greater number of species 
of Resedacee, is the result of the union, more or less protracted from 
the base upwards, of the seminiferous margins of two proximate 
ovarian leaves. The edges of these leaves, in their upper portion, 
where they are free, are generally folded inwards, and, above their united 
portion, downwards. Each ovarian leaf is surmounted by two stig- 
mata, being the summits of its two marginal nerves. These two 
