CLXII.— THE ALDER BUCKTHORN. 
Rhamnus Frangula Linne. 
HE F amily Rhamnacece, with the Vitacece, the Grapes, Virginian Creepers, etc. — 
a Family not represented among British plants — constitutes the Order 
Rhamnales. They are shrubs or small trees, some of them twining or climbing, 
and others, such as our Common Buckthorn ( Rhamnus catharticus Linn6), with 
spine-terminated branches. Their leaves are stipulate, simple, and entire ; the 
inflorescence cymose ; and the flowers inconspicuous and polysymmetric, but 
secreting honey, often massed together, and pollinated by insects. 
The number of parts in each of the floral whorls is often reduced to four, as 
in the Spindle-tree and its allies ; but the Rhamnacece differ from the Celastracece in 
having valvate, instead of imbricate, sepals, and stamens opposite to, instead of 
alternating with, their petals. In the Rhamnacece there is a cup-shaped receptacular 
tube, from the inner surface of which the honey is secreted, whilst the petals and 
stamens spring from its margin. The fruit, though dry and dehiscent in some 
members of the Family, is, in the Buckthorns and many others, fleshy and 
drupaceous, much as in the Holly, enclosing three, or less commonly two or four, 
one-seeded endocarps or “stones.” 
It is the fleshy portion of the berries of the Buckthorns that yields the various 
colouring substances which constitute one of the chief economic products of the 
group ; while fruit, bark, and, to some extent, the whole plant, contain bitter, and 
sometimes astringent, principles, often strongly purgative and employed as such 
medicinally. Thus a Mediterranean species, Rhamnus infeclorius Linne, is much 
grown at Kaisaryeh in Asia Minor, the ancient Caesarea in Cappadocia ; and its 
unripe fruits are exported from Smyrna under the name of Persian or Yellow 
Berries. Other species, such as R. saxatilis Linn£, R. Alaternus Linn6, and R. oleoid.es 
Linne, from the Mediterranean area, and our British R. catharticus Linne, yield some 
of the berries of commerce, those from France, known as Avignon Berries, being 
considered inferior to the Asiatic. They are used to give a yellow colour to 
morocco leather. The ripe berries of the British and Asiatic species alike, with the 
addition of alum or lime-water and gum arabic, form the sap-green or bladder- 
green of painters. Rather more than half a century ago considerable quantities of 
a beautiful green dye known as Lo-kao, or Chinese Green Indigo, were imported 
from China to Lyons for dyeing silk, and proved to be extracted from the bark of 
R. chlorophora Decaisne and R. ulilis Decaisne. A similar dye has been obtained from 
our own R. catharticus; but both are now alike superseded by aniline colours. Ripe 
Buckthorn berries are collected in Hertfordshire, Buckinghamshire, and Oxfordshire 
partly for the manufacture of sap-green and partly for that of the purgative Syrup 
of Buckthorn ; but, owing to the violence and uncertainty of its action, this latter 
substance has now been superseded by the so-called Cascara sagrada, or “ Sacred 
