84 THE BOOK OF BULBS 



of some sixty species, there are few not worth growing, 

 but corms of only a limited number are purchasable in 

 the ordinary course, and the best of these are named as 

 a guide. They are often found about six inches high, 

 but frequently grow much taller. Edulis has bluish- 

 white flowers ; iridioides, white, spotted yellow ; papi- 

 lionacea, pale-blue, spotted dark-blue ; spathacea (syn. 

 Dietes Huttoni), yellow ; and tricuspis, greyish yellow 

 and brown. Robinsoniana, also called Iris robin- 

 soniana, needs a greenhouse, and has white flowers and 

 handsome leaves with the habit of Phormium tenax. 

 The genus now includes the Vieusseuxias and Dietes, 

 which are sub-genera. 



ORNITHOGALUMS 



It is singular that the half-hardy Ornithogalums are 

 so little grown, as they are very easily managed in a 

 frame or unheated greenhouse, and will even do in a 

 warm border in the south. They like a light soil and 

 a sunny position, and to be well ripened after flowering. 

 The prettiest of the half-hardy species are O. aureum, 

 yellow ; O. arabicum, white with almost black centres, a 

 very effective plant ; and the pure white O. revolutum 

 They may be planted about three inches deep. 



OXALISES 



The tender Oxalises or Wood-Sorrels, are deserving 

 of more attention from those who have sunny frames or 

 unheated greenhouses, or even a sunny window, where 

 these flowers can open, for all are sun-lovers. They 

 like a light, rather sandy soil and may be planted in 

 autumn or early spring about two inches deep. They 

 are too numerous to detail, but I may name the follow- 

 ing as all worth growing, although the list might be 

 considerably extended. Arenaria, violet-purple ; arti- 



