ROBINIA. 



247 



ROCK WORK. 



ing for its splendid leaves and verj r ) 

 curious flowers and seed-pods ; but j 

 in the East Indies it becomes a tree. 

 The oil is expressed from the seeds. 

 When grown in England, the seeds 

 should be sown in a slight hotbed in 

 February, and the young plants re- 

 moved to the open border in May. 

 It should be grown in light rich soil, 

 well manured with decayed leaves, 

 and in a situation open to the sun. 



Ricotia. — Cruciferce. — A very 

 pretty little annual nearly allied to 

 Lumria, which only requires sowing 

 in the open border in April. See 

 Annuals. 



Ridging. — Throwing up ground 

 in ridges, in order to expose it more 

 thoroughly to the action of the weather. 

 This operation is most useful in 

 clayey soils, as the water freezing 

 separates the particles of the clay, 

 and lightens the soil ; and it is per- 

 formed by opening a trench, and 

 throwing up the ground so as to form 

 a kind of hillock sloping on both sides. 



Robinia. — Leguminosm. — Orna- 

 mental trees and shrubs, with long- 

 drooping racemes of flowers. The 

 common kinds of Robinia are gene- 

 rally called Acacias in gardens ; though 

 why this name has been given to 

 them, unless from their pinnate 

 leaves, which resemble those of the 

 true Acacia, it would be difficult to 

 say. The name of Locust, which is 

 applied to Robinia Pseud-Acacia 

 in America, also appears to have no 

 definite meaning, unless it alludes to 

 the leaves, which bear a very slight 

 resemblance to those of Ceratbnia 

 SH)qua,t\\e Locust Tree of Holy Writ. 

 The flowers of all the kinds of Robi- 

 nia are very handsome ; but the arbor- 

 escent species are not handsome trees, 

 from the liability of their branches to 

 be broken off by high winds, which 

 gives them a ragged and untidy ap- 

 pearance; and the wood, notwithstand- 

 ing the extravagant praises of Cobbett, 



is of very little value. The roots of 

 the Robinia also extend just under 

 the surface ; and thus a tree of this 

 genus occupies nearly twice the extent 

 of ground which would be taken up 

 by a tree of the same size of almost 

 any other kind. The shrubby kinds 

 of Robinia are also liable to the same 

 objections ; though the long racemes 

 of rose-coloured flowers of the Rose 

 Acacia ( R. luspida ) are so beauti- 

 ful, that no shrubbery should be 

 without it. All the Robiuias are 

 quite hardy, and they may be grown 

 in any soil, though they thrive most 

 in a rather rich sandy loam ; care 

 should be taken always to plant them 

 in a sheltered situation, as no plants 

 are more injured by high winds. They 

 are propagated by seeds, layers, cut- 

 tings, and suckers, which are produced 

 in great abundance. When Robinias 

 are raised from seed, the seeds should 

 be steeped for twenty-four hours in hot 

 water, before sowing; as unless this is 

 done, they will sometimes remain 

 in the soil tAvo years before they ger- 

 miuate. When grown in strong clay, 

 or in any moist soil, old trees of Ro- 

 binia Pseud-Acacia are very often 

 found, when cut dow r n, to be hollow 

 at the heart. Several plants formerly 

 considered to belong to Robinia, are 

 now distributed through the genera 

 Caragana, Halimodendron, &c. Of 

 these, the most beautiful are the 

 Caraganas — see Siberian Pea Tree ; 

 and the Halimodendron, or Salt Tree. 

 — See Halimodendron. 



Rocket. — See Hesperis. 



Rock cress. — See Arabis. 



Rock rose. — See Cistus. 



Rockwork is a very common orna- 

 ment in gardens; and, producing a 

 striking effect, it is introduced more 

 frequently than judiciously. Rock- 

 work may be divided into two kinds : 

 that which is intended to imitate 

 natural rocks, and that which is in- 

 tended merely as a nidus for rock- 



