248 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 thoms 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) , -B/ac^ Locust (in New England called Honey 

 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 Allcghanies; 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 



