310 RHAMNUS. [CLASS V. ORDER 1. 



diluents. The juice expressed from the unripe berries has a faint un- 

 pleasant odour, a bitterish acrid nauseous taste, and is of a yellowish 

 saffron colour ; it is used as a pigment, and a dye for staining paper, &c. ; 

 the juice of the riper berries is of a deep green, from it, by the addition 

 of a little alum or lime water, and a portion of gum arabic, is formed 

 by evaporation the sap green, used by painters. If the berries are 

 gathered when quite ripe, the juice is purple instead of green, contain- 

 ing a portion of saccharine matter; it soon ferments, forming acetic 

 acid, and the juice becomes of a reddish colour. The dried berries 

 sold in the shops under the name of French berries, are the unripe 

 fruit of this plant, which is frequently mixed with the useless fruits of 

 other plants, which do not possess the same property; but they are 

 readily known by not having four cells, as the fruit of this plant has. 

 The bark also affords a good yellow dye. 



2. R. Fran'gula, Linn. (Fig. 381.) Berry -bearing Alder, or Alder 

 Buckthorn. Without spines; leaves ovate, acute, entire; flowers all 

 perfect. 



English Botany, t. 250.— English Flora, vol. i. p. 329.— Hooker, 

 British Flora, vol. i. p. 119. — Lindley, Synopsis, p. 73. 



An erect shrub, with round, smooth, alternate, unarmed branches, 

 mostly long, slender, leafy, and clothed with a soft down at the ex- 

 tremities, the bark a smooth shining purplish brown. Leaves alternate, 

 ovate, or roundish, with an acute or accuminated point, round at the 

 base, the margin entire, of a smooth shining deep green, paler beneath, 

 with a strong mostly hairy mid-rib, and numerous straight parallel 

 veins, smooth or hairy, footstalk channelled above, downy, each having 

 at the base a pair of awl-shaped downy bractea, which shortly fall 

 away. Flowers perfect, (containing both stamens and pistil), mostly 

 numerous in fascicles from the axis of the leaves, each elevated on a 

 slender, smooth, or downy stalk, with a minute stipule about mid-way. 

 Calyx of five obovate downy erect segments, larger than the five alter- 

 nating petals, which have a waved margin attached into the contracted 

 throat of the calyx, with the short stamens before them, and partly 

 enveloping them. Anthers ovate, of two cells. Stigma nearly sessile, 

 capitate, cloven. Fruit a dark purple, somewhat fleshy berry of 

 two or three single seeded cells, surrounded at its base with the per- 

 sistent calyx, contracted into a shield-like plate. 



Habitat. — Woods and shady places ; frequent in England. Near 

 Anchincruive, Ayrshire, Scotland. — Mr. Smith. On a small island, 

 called the Crcagh Bog, in Lough Beg, County of Dcrry, Ireland.— 

 Mr, D. Moore. 



Shrub ; flowering in May and June. 



The Black Alder contains in all its parts, but particularly in the 

 bark, a bitter astringent principle, which has been used in the foiin of 



