CRUCIFER.E. 41 



and the variegation has the effect also of depreciating the 

 beauty of the flowers, which is very obvious when the two sorts 

 are grown side by side. 



Arabis i^Rock-Crcss). — This is a rather numerous family, and 

 presents a greater variety of colour in its species than Alyssuni: 

 but I do not think a more extensive selection would be proper, 

 for though easily-managed hardy plants, only two or three 

 species are far enough removed from weediness to be admitted 

 among ornamental plants. Those included in the following 

 selection are very easily cultivated, thriving in most soils and 

 in almost any situation. They are, however, most character- 

 istic of rockwork ; and even when grovv^n in borders and other 

 flat surfaces have the best effect when raised in hillocks. They 

 are of more straggling grov/th, if A. lucida is excepted, than the 

 Alyssinns, and require a little more attention where trimness 

 and smoothness of surface are required; but the pegging neces- 

 sary to secure this object may be turned to account for the 

 purpose of increase, as by this means alone, owing to the ten- 

 dency of all the species to strike root from their trailing stems 

 into the ground, if they are kept firmly attached to it, a larger 

 increase may be obtained in one season from a plant than by 

 means of cuttings or division. Cuttings, if they should be 

 resorted to for increase, require the same treatment as has been 

 already noticed for Alysstwi, only the bell-glass is not so indis- 

 pensable. They must be taken as soon as growth is active ; 

 and as they are of an unhandy style — always top-heavy — in the 

 case of the species of the albida type, as much of the flexible 

 cord-like stem should be taken along with the rosette of leaves 

 as is convenient, in order to provide means of fastening the 

 cutting securely in the soil. Seeds also may be used sown out 

 of doors in any spare spot, but only the specific forms may be 

 raised in this way with certainty ; the variegated varieties do 

 not come true. 



A. albida, syns. A. caucasica and A. crispata {Sicilian Rock- 

 Cress). — This is the best known, and one of the best, of the 

 family. The plant forms diffuse patches of running stems, 

 clothed at the extremities with rosettes of pale-green leaves, 

 wavy and toothed on the margins, and clothed with greyish 

 hairs. Flowers white, in profuse loose panicles about a foot 

 high, appearing in greatest profusion from March till June, but 

 flowering more or less earlier and later than those months. A 

 most valuable plant for spring flower-gardening, for rockwork, 

 for the mixed border, and for naturalising on dry banks, about 

 ruins, and in open woods. The variety named A. albida varie- 

 gata is a beautiful and useful plant for purposes of edging and 



