Naturalisation in Extra- Tropical Countries. 413 



Rhamnus Alaternus, Linne. 



Countries round the Mediterranean Sea. A hedge-shrub, becom- 

 ing arborescent, thus gaming a height of 20 feet. It strikes 

 readily from cuttings. G. Don admits it as a splendid honey-plant. 



Rhamnus alnifolius. L'Heritier. (R. Purshianus, B.C.) 



From California to Oregon and British Columbia. Allied to R. 

 Carolinianus (Walter). Reaches a height of about 20 feet. Leaves 

 deciduous. This species furnishes as " Cascara Sagrada " its bark, 

 famed for cathartic properties ; about 300,000 Ibs. are at present 

 annually used therapeutically ; the fruits are also powerfully 

 aperient. R. Californica (Chamisso) acts similarly, according to 

 Dr. J. Gr. Steele. R. crocea (Nuttall) has also some medicinal virtue. 



Rhamnus eatharticus, C. Bauhin. 



The Buckthorn. Middle and Southern Europe, North- Africa, 

 Middle Asia. It can be utilised as a hedge-plant. The berries are 

 of medicinal value, as indicated by the specific name. The foliage 

 and bark can be employed for the preparation of a yellow and green 

 dye ; the juice of the fruit mixed with alum constitutes the " sap- 

 green " of painters. The plant is hardy in Norway to lat. 60 48 '. 

 R. Dahuricus (Pallas) is a closely cognate species. 



Rhamnus chlorophorus, Lindley. 



China. From the bark a superior green pigment is prepared. 

 R. utilis, from the same country, serves for the like purpose. This 

 kind of dye is particularly used for silk, and is known as Lokao. 



Rhamnus Frang-ula, Linne. 



Europe, North-Africa, Northern and Western Asia. Endures the 

 climate of Norway to lat. 64 30' [Schuebeler], A tall shrub with 

 deciduous leaves. The flowers are particularly grateful to bees 

 [G. Don]. The wood one of the very best for gunpowder. Recom- 

 mended by Sir Joseph Hooker to be grown on the coppice-system 

 for this purpose. The bark is valuable as a cathartic ; yields also 

 a yellow dye. R. purpureus (Edgeworth) is an allied Himalayan 

 species. 



Rhamnus G-reecus, Eeuter. 



Greece. From this shrub and to no less extent from the allied 

 R. prunifolius (Sibthorp) are derived the green dye-berries col- 

 lected in Greece, according to Dr. Heldreich. These shrubs grow 

 on stony mountains up to 2,500 feet. 



Rhamnus infectorius, Linne. 



On the Mediterranean Sea and in the countries near to it. Hardy 

 still at Christiania. The berry-like fruits of this shrub are known 

 in commerce as Graines d'Avignon and Graines de Perse, and pro- 



