ROBINIA DUBIA (_syns R. echiuata_ and _R. ambigua_).--A very pretty
garden hybrid form, said to have for its parentage R. Pseud-Acacia and
R. viscosa. It is of quite tree-like growth and habit, with unusually
short spines, and Pea-green foliage. The flowers are produced pretty
freely, and are of a pale rose colour, and well set off by the
light-green leaves, over which they hang in neat and compact spikes.
R. HISPIDA.--Rose Acacia. North America, 1743. Amongst large-growing
shrubs this is certainly one of the most distinct and handsome, and at
the same time one of the hardiest and readiest of culture. Under
favourable conditions it grows about 16 feet high, with large oval or
oblong leaflets, and having the young branches densely clothed with
bristles. The flowers, which are individually larger than those of the
False Acacia, are of a beautiful rosy-pink, and produced in June and
July. It is a very ornamental, small growing species, and one that is
peculiarly suitable for planting where space is limited. R. hispida
macrophylla (Large-leaved Rose Acacia) is rendered distinct by its
generally more robust growth, and by its larger foliage and flowers. The
species, however, varies a good deal in respect of the size of leaves
R. PSEUD-ACACIA.--Common Locust, Bastard Acacia, or False Acacia. North
America, 1640. A noble-growing and handsome tree, with smooth shoots,
and stipules that become transformed into sharp, stiff spines. The
flowers are in long racemes, pure-white or slightly tinged with pink,
and with a faint pleasing odour. This species has been sub-divided into
a great number of varieties, some of which are very distinct, but the
majority are not sufficiently so to warrant special attention. The
following include the best and most popular kinds:--R. Pseud-Acacia
Decaisneana, a distinct form bearing light pinky flowers; R.
Pseud-Acacia Bessoniana, with thornless branches and a dense head of
refreshing Pea-green foliage; R. Pseud-Acacia angustifolia, with narrow
leaves; R. Pseud-Acacia aurea, a conspicuous but not very constant
golden leaved form; R. Pseud-Acacia inermis, of which there are weeping,
upright, and broad-leaved forms, has narrow leaves that are glaucous
beneath, and the characteristic spines of the species are wanting or
rarely well developed. R. Pseud-Acacia monophylla is very distinct, the
leaves being entire instead of pinnate; while R. Pseud-Acacia crispa has
curiously-curled foliage. Then there is the peculiar R. Pseud-Acacia
tortuosa, of ungainly habit; R. Pseud-Acacia umbraculifera, with a
spreading head; R. Pseud-Acacia sophoraefolia, the leaves of which
resemble those of Sophora japonica; and R. Pseud-Acacia amorphaefolia,
with very large foliage when compared with the parent tree. The above
may be taken as the most distinct and desirable forms of the False
Acacia, but there are many others, such as R. Pseud-Acacia colutoides,
R. Pseud-Acacia semperflorens, and R. Pseud-Acacia Rhederi, all more or
less distinct from the typical tree.
R. VISCOSA (_syn R. glutinosa_).--Clammy Locust. North America, 1797.
This is a small-growing tree, and readily distinguished by the clammy
bark of the younger shoots. Flowers in short racemes, and of a beautiful
rose-pink, but varying a good deal in depth of tint. It is a valuable
species for ornamental planting, and flowers well even in a young state.
Few soils would seem to come amiss to the Acacias, but observations
made in many parts of the country conclusively prove that the finest
specimens are growing on light, rich loam overlying a bed of gravel.
They are propagated from seed, by layers, or by grafting.
Other R Tree Species