CHAP. xLi. legumina'ce.i;. KOBI'N/-^. 611 



young, but as it grows old they spread out hori- 

 zontally. They are armed with strong hooked 

 prickles, and not with spines or ligneous thorns ; 

 the former being only attached to the bark, like 

 the prickles of the common rose or the bramble; 

 and the latter proceeding from the wood, like the 

 spines of the hawthorn, cockspur, and other 

 thorns. The leaves of the robinia are composite, 

 the leaflets being sessile, and 8, 10, or even 12, 

 with an odd one. Their texture is so fine, and 

 their surface so smooth, that the dust which falls 

 on them will hardly lie ; which last circumstance 

 renders the tree particularly eligible for planting 

 along road sides, in the neighbourhood of towns, 

 or in great thoroughfares. The flowers are disposed 

 in pendulous bunches, white or yellowish, and are most agreeably fragrant : they 

 are succeeded by narrow flat legumes, about 3 in. long, each containing 5 or 6 

 small seeds, which are commonly brown, but sometimes black. These seeds, 

 when taken out of the pod, and exposed to the air, will hardly retain their vege- 

 tative properties two years, but, when kept in the pod, they will remain good a 

 year longer ; and, when the pods are buried 5 ft. or 6 ft. under the surface, in 

 dry soil, they have been known to keep 7 years, without losing their vitality, 

 and would probably retain it for a much longer period. The dimensions of the 

 tree, in its native country, vary much with the soil and climate in which it 

 grows. In Kentugky, the tree sometimes attains the height of 70 ft. or 80 ft., 

 with a trunk 4 ft. in diameter ; but it does not arrive at half that size at Harris- 

 burgh, in Pennsylvania. On the trunk and large limbs of the old robinias, the 

 bark is very thick, and deeply furrowed ; but on the young trees it is com- 

 paratively smooth for the first 10 or 13 years. The young tree, till the 

 trunk attains the diameter of 2 in. or 3 in., is armed with formidable prickles ; 

 but these disappear altogether as it grows old, and they are wanting, in some 

 of the varieties, even when they are young. The wood, which is commonly 

 of a greenish yellow colour, marked with brown veins, is hard, compact, and 

 susceptible of a bright polish : it has a good deal of strength, and is very 

 durable; but it has not much elasticity, and is somewhat liable to crack. The 

 tree has one property almost peculiar to it, that of forming heart-wood at 

 a very early age, viz. in its third year ; whereas the sap-wood of the oak, 

 the chestnut, the beech, the elm, and most other trees, does not begin to 

 change into heart, or perfect, wood, till after 10 or 15 years' growth. (Alic/ix.) 

 In Britain, in the neighbourhood of London, the Robin/a Pseud-zlcsicia some- 

 times attains as great a height as it does in any part of America ; but, north of 

 London, it is as small as it is in the north-east of Pennsylvania, or smaller. 

 It grows with great rapidity when young; plants, in 10 years from the seed, 

 attaining the height of from 20 ft. to 30 ft., or even 40 ft. ; and established 

 young plants producing shoots 8 ft. or 10 ft. long in one season. When the 

 tree has once attained the height of about 40 ft. or 50 ft., it grows very slowly 

 afterwards; but, whatever height it attains, there are very few specimens to be 

 met with in England, that have more than 30 or 40 cubic feet of timber in 

 the trunk. At 50 or 60 years of age, the trunk is not greatly increased in 

 girt; but at that age the branches often contain as great a bulk of timber as 

 the trunk, though, from not being straight, that timber is comparatively of 

 little value, except for fuel. The greatest bulk of timber contained in any 

 robinia that we have heard of is in one at Taverham, in Norfolk, which 

 contains 89i cubic ft. {Withers' s Trent., p. 234.) It stands among some 

 silver firs, which are presumed to be about the same age, and which contain 

 nearly 3 loads (about 150ft.) of timber each; thus affording a tolerable cri- 

 terion of the comparative rate of growth of the two trees. The trees of this 

 species, and of several of its varieties, in the garden of the Horticultural 

 Society, and in the arboretum of Messrs. Loddiges, have attained the 



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