Part II. ARAB IS. 149 



make the plant very distinct from any flower of the same order 

 in cultivation. It varies a'''good deal, but there is no difficulty 

 in selecting a strain of the deepest and brightest rose. ■ It is 

 impossible to have anything more effective than healthy tufts of 

 this plant in the month of April. Whether it prove sufficiently 

 hardy to be a generally useful plant for the open air or not, it is 

 certain to prove a very useful frame plant. It is best raised 

 every year from seed, which, like most cruciferous plants, it 

 yields freely. In all mild districts, and on light soils, plants 

 should be tried out every winter, for there is no out-door flower 

 which surpasses it in pleasing brilliancy during the month of 

 April. The brighter forms are remarkably effective a consider- 

 able distance off, and therefore some plants should be placed in 

 positions on the rockwork where they may strike the eye from 

 afar. A native of North America, easily increased by seed. 



Among other kinds of Arabis, A.procurrens a dwarf spreading 

 kind, with shining leaves and small whitish flowers,' is often 

 grown, but is not worthy of culture, There is, however, a 

 brilliantly variegated form of it {A. ' ■procurrens variegatd) 

 which is worthy of a place in a collection of silvery and 

 variegated hardy plants. The prettiest of the variegated 

 Rock Cresses is A. lucida variegata. It forms vefy neat 

 and effective edgings in winter, spring, and summer flower 

 gardens, from its striking and distinct character is effective 

 on rockwork, and thrives best and is easiest to increase by 

 division in open, sandy, and yet moist soil. .The best time 

 to divide it is early in autumn, April, or very early in May. It 

 need scarcely be added that the flowers should be removed 

 when they appear. I have grown the green form of the plant, 

 but it is in no sense ornamental. A. purpurea, an interesting 

 species for botanical, large, or curious collections, and bearing 

 pale bluish and lilac flowers, is not worthy of general culti- 

 vation while we possess such brilliant plants as the purple 

 Aubrietias. A. arenosa, from the South of Europe, is a pretty 

 annual kind that may prove useful in the spring garden, and 

 which might be naturalised on old ruins or dry bare banks. 

 A. petrcea (Northern Rock Cress) is a neat, sturdy little 

 plant, with pure white flowers, a native of some of the higher 

 Scotch mountains, and very rarely seen in cultivation, but when 

 well developed on a moist yet well-exposed spot on rockwork is 

 very pretty. There is a form of it with a purple tinge on the 



