2.48 Trees for Shade and Ornament 
four to five hundred species, varieties, and hybrids, medium-sized to 
(mostly) small trees and shrubs, which besides their pod-like fruit, 
have also similar, small leaflets, forming a graceful foliage, generally 
beset with thorns or spines. Some have striking flowers, which form 
an additional ornament. They are adaptive to poor soils, and are 
very light-needing. 
Robinia. Three native species have their valuable points: R. 
pseudacacia Linn . (85), Black Locust (in New England called H oney 
Locust), the best known; a small to medium-sized tree, is hardy 
everywhere. It is most interesting and beautiful when in flower, with 
large, pendent, fragrant, white clusters (May, June), set off by the 
yellowish-green to dark green foliage. In winter the unattractive pods 
persist, and the straggling branch system, with rough, ridgy bark on 
the old trees, and short prickles on the smooth bark of the branches, 
detracts from its looks. It excels in its rapidity of growth, the ease of 
transplanting, and adaptation to almost any soil, even the poorest and 
driest; but it is variable in outline according to the site, from the hand- 
some, roundish or elliptical form and upright habit on cool, rich loam 
and not too poor sand (under such conditions making a fine lawn 
tree), to the ugly, straggling, and unsatisfactory form on compact clay 
soil, especially in old age, when branches here and there begin to die. 
To be used mainly for grouping by themselves on knolls and to cover 
sandy or gravelly wastes; singly, near houses, and on small grounds for 
cheap, rough hedges. Unfortunately, a borer working in the lower 
trunk disfigures, although rarely kills, the tree; a leaf fungus not infre- 
quently attacks it, and it has the bad habit of suckering from the 
shallow roots. Easily propagated by cuttings. It grows very rapidly, 
but not persistently, and makes a hard, durable wood, fit for fence 
posts, etc. 
A variety, inermis (86), without thorns, has usually a darker hued 
foliage. 
R. viscosa Vent. (87), Clammy Locust, so called from its sticky branch- 
lets and leaf stems, smaller than the former (ten to fifteen feet down 
to a shrub), is similar to the preceding species, but with larger clusters 
of rose-pink flowers, appearing later and continuing longer. 
R. hispida Linn. (88), Rose Acacia, appearing more often as a low 
shrub than a tree; from the southern Alleghanies; a very desirable or- 
nament and the hardiest of all; large rose-colored flowers appear very 
early in life (June and July); more prickly than the other varieties; has 
