THE BUCK-THORN TRIBE. 121 



stance, few of the genera have a dry seed-vessel, but they 

 more generally bear a succulent fruit ; spines also are 

 most frequently absent, or at least are alterations of 

 buds, and not of stipules ; and the leaves are most 

 commonly not ribbed ; but they all agree in the four 

 characters just selected. 



The A lat emus, one ofthose beautiful evergreen shrubs, 

 which give such a peculiar charm to English garden 

 scenery. Buck-thorn, so useful as a covert for game, 

 and the berry -hearing, or black Alder of our copses, 

 are various species of the genus Rhamnus, which is 

 known from Paliurus by the fruit being succulent, the 

 leaves ribless, and the stipules spineless. It contains 

 several species of some importance for their dyeing 

 properties ; sap-green, for instance, is a preparation 

 of the fruit of Buck-thorn (Rhamnus catharticus) ; 

 the " French berries" of the shops, from which so beau- 

 tiful a yellow is obtained, are the unripe fruit of the 

 same plant ; and yellow morocco leather acquires its 

 colour from the juice of Rhamnus infectorius, and other 

 southern species. The berries of all are unfit for food, 

 and produce extremely unpleasant consequences when 

 taken into the stomach. 



Far otherwise is the case with the fruit of the Jujube 

 (Zizyphus Jujuba), which, as I fear you know only too 

 well, is mixed with some powerful gluten, and manu- 

 factured into lozenges, which are taken in coughs and 

 colds. 



Besides these, we have among the ornamental plants 

 of the Jujube Tribe, the superb Ceanothus azureus, 

 whose innumerable clusters of light-blue flowers have 



