32 ALPINE PLANTS 
all their own, and they add to the aged and established 
appearance of the rock-garden of adequate extent. A 
rockery of quite small size can scarcely be an appropriate 
place for trees, but there are shrubs of dwarf and restricted 
growth, which can, with advantage, be distributed over 
even a verysmall mound. The Cistus, and Helianthemums, 
shrubby Potentillas, Hypericums and Veronicas, especially 
those like cupressoides, salicornoides, Hectorii, and also 
Bidwellii, being capital substitutes for pigmy trees, and 
having the additional advantage of providing flowers in 
season, as well as tree-like growth and foliage. Ferns are 
indispensable associates of the flowering plants of the 
rock garden, and some of the ornamental grasses and 
reeds must be used, especially if the rock-work contains 
a pool, streamlet, or approaches the margins of a sheet 
of water. 
Bulbs, too, of many kinds are admissible and desirable, 
but exception should be taken to Dutch Hyacinths, and 
even the ordinary bedding Tulips seem out of place ona 
rockery, although an occasional clump of one or other of 
the tulip species will appear quite at home. The planting 
of scarlet Geraniums, blue Lobelia, or double Begonias on 
rockeries cannot be tolerated, but certain annuals of 
dwarf or trailing growth intermix with the permanent 
occupants of the rock garden quite well. There are indeed 
true alpines of annual and biennial character which are 
extremely useful. 
