ROCK-GARDEN IRISES 79 



/. arenaria, which, as its name implies, likes sand, but not 

 pure sand without nourishment. The slender rhizome 

 creeps about just under the surface, and should spread in 

 all directions. Then in April many of the growths are 

 seen to be getting plump, and by May they burst out into 

 bright, clear yellow flowers with thick orange beards. It 

 is unfortunate that the plant seems almost to exhaust itself 

 by overflowering. It needs therefore to be given fresh soil 

 about every two years, or at least be top-dressed in spring. 

 The surface soil may be nearly pure sand, but an inch or 

 two down the roots should be able to find something more 

 nourishing, though still light and warm. The brilliance of 

 a good mass of this little gem among Irises is not easily for- 

 gotten. Seed may easily be obtained by artificial pollination 

 of the flowers, and it germinates fairly readily. Young 

 plants grow very fast, and soon cover quite a large space 

 with their wide-creeping rhizomes, and produce six or 

 eight flowering stems in their second season. 



Near /. arenaria might well be grown such small Oncocy- 

 clus species as paradoxa, iberica, acutiloba, &c., and their 

 darker flowers will provide a foil for the brilliant yellow of 

 the former species. The sharp drainage of the rock garden 

 will also be in their favour. 



So far there have been mentioned those small Irises 

 which seem to be very little known, but which only need to 

 be known to be installed in most rock gardens. We must 

 not, however, forget that even the most negligent of gar- 

 deners may obtain a fine display of colour among the 

 rocks in April and May, by planting largely the more 

 common small, bearded Irises, such as /. chamceiris, I. 

 olbiensis, I. bosniaca, and /. balkana, even if he does not 



