R. GLABRA (syns R. caroliniana, R. coccinea, R. elegans, and R. sanguinea).—­Smooth or Scarlet Sumach.  North America, 1726.  A smaller tree than the last, with leaves that are deep glossy-green above and whitish beneath.  The male tree bears greenish-yellow flowers, and the female those of a reddish-scarlet, but otherwise no difference between the trees can be detected.  R. glabra laciniata (Fern Sumach) is a distinct and handsome variety, with finely cut elegant leaves, and a dwarf and compact habit of growth.  The leaves are very beautiful, and resemble those of the Grevillea robusta.  It is a worthy variety.

R. SUCCEDANEA.—­Red Lac Sumach.  Japan, 1768.  This is not often seen planted out, though in not a few places it succeeds perfectly well.  It has elegant foliage, each leaf being 15 inches long, and divided into several pairs of leaflets.

R. TOXICODENDRON.—­Poison Oak or Poison Ivy.  North America, 1640.  This species is of half-scandent habit, with large, trifoliolate leaves, which turn of various tints of red and crimson in the autumn.  It is quite hardy, and seen to best advantage when allowed to run over large rockwork and tree stumps in partial shade.  The variety R. toxicodendron radicans has ample foliage, and is suited for similar places to the last.  The leaves turn bright yellow in the autumn.

R. TYPHINA.—­Stag’s Horn Sumach, or Vinegar Tree.  A native of North America (1629), and a very common shrub in our gardens, probably on account of its spreading rapidly by suckers.  It is, when well grown, a handsome and distinct shrub or small tree, with large, pinnate, hairy leaves, and shoots that are rendered very peculiar by reason of the dense hairs with which they are covered for some distance back.  The dense clusters of greenish-yellow flowers are sure to attract attention, although they are by no means pretty.  R. typhina viridiflora is the male-flowered form of this species, with green flowers.

R. VENENATA (syn R. vernix).—­Poison Elder, Sumach, or Dogwood.  North America, 1713.  This is remarkable for its handsome foliage, and is the most poisonous species of the genus.

All the Sumachs grow and flower freely in any good garden soil, indeed, in that respect they are not at all particular.  They throw up shoots freely, so that increasing the stock is by no means difficult.

RIBES.

RIBES ALPINUM PUMILUM AUREUM.—­Golden Mountain Currant.  The ordinary green form is a native of Britain, of which the plant named above is a dwarf golden-leaved variety.

R. AUREUM.—­Buffalo Currant.  North-west America, 1812.  In this species the leaves are lobed and irregularly toothed, while the flowers are yellow, or slightly reddish-tinted.  It is of rather slender and straggling growth.  R. aureum praecox is an early-flowering variety; and R. aureum serotinum is valued on account of the flowers being produced much later than are those of the parent plant.