IRISES FOR THE ROCK-GARDEN AND THE WATERSIDE. 455 



Waterside Irises. 



Water-loving Irises thrive well by the side of a small stream where 

 the water supply is at a fairly constant level ; but they do best by the 

 edge of a pond or lake when the water can be kept at the same height by 

 automatic means. It is far more difficult to grow them by a pond which 

 has no outlet and is merely fed by surface drainage. In this case, during 

 winter and spring the Irises are probably submerged a foot or more, while 

 in summer and autumn the pond shrinks and they are left high and dry. 

 If waterside Irises like to have their feet cool and moist, an essential 

 point in their welfare is to have their heads in full sunshine. Many will 

 do well in a fairly damp, sunny border, and will flower abundantly. But 

 if the stream or pond be overshadowed by large trees, they will only be a 

 source of disappointment from the few flowers they will produce. They 

 are quite hardy and grow rapidly and vigorously if they are given plenty 

 of good rich soil and well-rotted manure, but we want more than an 

 abundant leafage. If there are waterfowl on the pond or lake, it will be 

 necessary to enclose the water-garden with wire-netting, as both wild duck 

 and moorfowl are most destructive to root and shoot. 



The following are suitable species for a clamp situation, and do not 

 object to being submerged during some part of the year. All the forms 

 of Iris sibirica, blue and white, thrive in the water-garden, and with 

 their narrow green foliage and slender branching stems, bearing a 

 succession of small elegant flowers, are quite pretty, the best form being 

 Iris orientalis, with its handsome dark blue flowers. These flower with 

 Primula japonica and together form exceedingly brilliant and effective 

 groups. The North American swamp-loving species are also ornamental. 

 Iris virginica (fig. 129) has deep lilac flowers, with lilac-blue pencillings 

 on a white ground, and has a flat-topped appearance from the small size 

 of the standards. Iris longipetala (fig. 130) is attractive from its loose 

 wavy outline and delicate colouring and marking in pale lilac and white, 

 the variety superba being particularly harmonious in silvery lilac-grey and 

 white, with a narrow yellow stripe. Other graceful species in shades of 

 blue are Iris missouriensis, Iris Tolmieana, and Iris tridentata. Iris 

 spuria is rather a tall species with narrow foliage and violet-blue flowers, 

 with an effective broad yellow blotch on the falls. A smaller species 

 which is not intolerant of a moist habitat is Iris graminea (fig. 130), 

 with bright grassy-green leaves and small flowers of a vivid combination 

 of crimson and blue, which are succeeded by a very deeply-ribbed capsule. 

 The tall late-flowering Flags follow in succession after these. Iris ochro- 

 leuca is very handsome, with yellow and white flowers, several being open 

 at the same time above each other on the stem. Other yellow ones are 

 Iris aurea and Iris Monnieri, while the common yellow Flag Iris Pseud- 

 acorus is at its best in the form with variegated foliage. The grandest 

 of all is the fine Japanese Iris, in its cultivated forms, generally called 

 Iris Kaempferi. It has both single and double flowers and a wide range 

 of colouring. The huge flat-topped flowers, in wonderful shades and 

 blendings of grey, mauve, pink, blue and white, with gold introduced here 

 and there, well reward careful cultivation. 



