THE ROCK GARDEN 181 



panula caespitosa, the most familiar of Alpine Hare- 

 bells, will thrive almost anywhere, especially if its roots 

 and long suckers can run under a rock. It should 

 not be placed near any delicate Alpines, as it is very 

 encroaching. There are white and pale blue varieties. 

 It is, of course, a true perennial; but seedlings flower 

 later than old plants, and remain in blossom until the 

 frosts. Therefore it is particularly useful when treated 

 as an annual. Campanula carpatica will also flower 

 the same year from seed; but it is rather a large plant 

 for a small rockery. 



Of all these plants that can be grown as annuals 

 Linaria alpina is the most useful, since it will scarcely 

 smother the most minute Alpines when growing in 

 the poor soil which most small Alpines like, while in 

 better soil and on the north side of the rock garden 

 it grows much stronger and will give the right amount 

 of shade to plants such as the Alpine primulas, Saxi- 

 fraga apiculata, and Morisia hypogaea. It multiplies 

 so quickly by means of self-sown seedlings that it be- 

 comes almost a weed, but its growth is so slight and 

 delicate that scarcely any plant can be harmed by it. 

 There are also some true annuals that can be used 

 to brighten the rock garden in autumn, such as the 

 dwarfest form of Alyssum maritimum and the delicate 

 little lonopsidium acaule, which, if sown early in the 

 spring, will seed and flower again from self-sown seed- 

 lings in the autumn. Nor is there any reason in the 

 nature of things why Lobelia, a beautiful plant made 

 unpopular by misuse, should not be employed in this 



