It enjoys light soil and a well drained situation, such as the edge of a border, where strong growing kinds cannot damage it, or on rockwork, where it will be fully exposed to the sun. To be effective, it should be grown into strong clumps, which may easily be done by annually giving a top-dressing of leaf-mould; the older parts of the plant will remain perfectly sound and healthy for years. When it is desirable to propagate it, it may best be done in April, when the tufts should be carefully divided, and its short roots made firm in the soil by one or two stones being placed near.
Flowering period, January to April.
Saxifraga Cæsia.
Silver Moss, or Grey Saxifrage; Nat. Ord. Saxifragaceæ.
One of the alpine gems. This has been grown in English gardens since 1752, yet good specimens are rarely met with, though its culture is simple and easy. It is found wild on the Alps of Switzerland, Austria, and the Pyrenees. To the lover of the minute forms of genuine alpine plants, this will be a treasure; it is very distinct in form, habit, and colour. Its tiny rosettes of encrusted leaves can scarcely be said to rise from the ground, and the common name, "silver moss," which it is often called by, most fittingly applies; but perhaps its colour is the main feature of notice. The meaning of its specific name is grey, to which it certainly answers; but so peculiar is the greyness that a more definite description may be useful, in giving which I will quote that of Decandolle and Sprengle: "The lavender-blue is a pale blue (cæsius); it is mixed with a little grey." This exactly answers to the colour of the pretty Saxifrage under notice, and it is far from a common one in foliage.
The flowers differ but slightly from those of other encrusted forms of the genus, but they are a creamy white, arranged in small panicles on short and slender stems. They are sparingly produced in May and June. The leaves are ¼in. long, aggregate or in miniature rosettes; in shape, linear-oblong, recurved, and keeled. The upper surface is concave, having marginal dots, evenly disposed; the dots are bright and excavated, and some of the leaves (those of the stems) are scale formed. The glaucous or lavender-blue colour is beautifully enlivened with the crystal dots. Its habit reminds one of the more distinct forms of lichens, and, when it is grown with suitable companions on rockwork, it has a happy way of showing and adapting itself in such situation; besides, its colour then shows with more effect.
Fig. 82. Saxifraga Cæsia Major.
(1, single rosette, natural size.)
There is a variety of this species not yet in general cultivation, and it cannot be too strongly recommended to lovers of the finest forms of rock or alpine plants. It is called S. c. major (see Fig. 82). The name at once suggests the main difference from the type, but there are other features quite as marked as that of its extra size in all its parts; the foliage is more crowded, which seems to cause the largest leaves to become more erect, and the habit, too, perhaps from the same cause, is ball shaped; the small rosettes of thick encrusted leaves, from the manner in which they are packed together, form a rigid mass, which differs widely both in detail and effect from any other Saxifrage I know.