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Chapter XVIII. 



Order XVIII.— RHAMNE.E. The Buckthorn Family. 



Chaeactek of the Order. — Trees or slirubs. Leaves 

 alternate, rarely opposite, stipulate. Flowers regular, her- 

 maplirodite. Calrx, superior or inferior, 4 or 5-toothecl or 

 lobed ; lobes triangular, valvate, often having a raised ridge 

 down the eentre, and an incurved thickened tip. Petals 0. or 

 4 or 5, minute, scale-like, very concave, placed between the 

 teeth of the calyx, and often smaller than them. Stamens, 4 

 or 5, very small, inserted witli the petals, opposite to, and often 

 hooded by them. Disk hypogynous or epigynous. Ovary, 



superior or inferior, 3-celled ; style, 1 ; stigma, capitate or 

 3-fid ; ovule solitary, and erect in each cell. Fruit of 3 cocci, 

 either free and subtended by the calyx, or more or less 

 immersed in, or adnate to the calyx ; cocci often crustaceous, 

 lenticular, dehiscing down the inner face. Seed, erect ; 

 albumen, fleshy; embryo, large; cotyledons, orbicular; 

 radical straight, terete. — Eaiidbooi- of the Neio Zealand Flora, 

 p. 42. 



Descriptiox of the Order. 



OIBRACES trees or shrubs inhabiting the tropics, in the mountainous 

 regions of India and Abyssinia, and the temperate countries of both 

 bemis2)heres. The majority of the species are shrubs, varying from one 

 to eight or ten feet high, though some occasionally grow as high as fifteen 

 or twenty feet, and form small trees, many of them being armed with 

 stout spines. The Alaternus {JR. alatenius), is an evergreen shrub or 

 small tree, native of the South of Europe and North of Africa, of which several varieties 

 are gro-mi for ornamental pur])oses in English gardens. It has smooth, serrated leaves; 

 varying from egg-shaped to elliptical or lance-sbaj)ed, and green flowers of separate sexes, 

 ■R-ithout petals. It was introduced into Britain in 1629. B. catharticus, the Purging 

 Buckthorn, is a native of Britain. It is a stiff, very much branched shrub, growing 

 from five to ten feet high, frequently having branches terminating in a sharp thorn-like 

 point. The flowers are yellowish-green, with very narrow petals, and grow in dense 

 clusters. The berries, which are black and shining, are about the size of a pea. The 

 juice of the unripe berries is of the colour of saffron, and is used for staining jiajier. The 



