THE BUCKTHORNS 31 
and are enclosed by seven or eight pairs of over- 
lapping scales, which are stipules in origin. The 
leaves have their margins rolled inwards in the bud 
and are in crowded tufts on the dwarf shoots and in 
sub-opposite pairs on the long shoots; they are 
elliptical, with sharply-toothed margins and a short 
abrupt point, downy on the stalk and under-surface 
when young, and of a dark green, which becomes 
yellowish towards autumn. Their midribs give off 
two or three secondary veins on either side at an 
acute angle which sweep towards the apex in an 
elliptical curve. On the other hand, the slightly 
angular, violet-tinged twigs of the Alder Buckthorn 
bear small grey hairy buds without scales; and its 
leaves, when unfolded, are reversedly egg-shaped, with 
no teeth on their margins and with eight or nine 
secondary veins on either side of their midribs. The 
two species agree in having small half-moon-shaped 
leaf-scars, each marked by the terminations of three 
veins; and, as we have seen, the lenticels are suf- 
ficiently prominent to have attracted the notice of 
Parkinson, who speaks of them as “ white spots.” 
The flowers of both species are alike individually 
minute, but those of R. catharticus are yellowish- 
green, and generally in dense clusters on the dwarf 
shoots of the previous year ; they are dicecious, having, 
that is, staminate and pistillate blossoms on distinct 
bushes ; and their parts are in fours—four sepals, four 
petals, four stamens, a style generally four-branched, 
and a four-seeded ovary. The few greenish-white 
blossoms in the axils of the leaves of the Alder Buck- 
thorn, though similar in the cup-shaped base of the 
