74 THE WILD GARDEN. 
persed over the central and southern parts of England and 
Ireland. Plant it not far from the margin, and it likes rich 
muddy soil. The common Arrow Head (Sagittaria), very 
frequent in England and Ireland, but not in Scotland, might 
be associated with this; but there is a very much finer double 
exotic kind, which is really a handsome plant, its flowers 
white, and resembling, but larger than, those of the old white 
Double Rocket. This used to be grown in abundance in the 
pleasure gardens at Rye House, Broxbourne, where it filled a 
sort of oblong basin, or wide ditch, and was very handsome in 
flower. It forms large egg-shaped tubers, or rather receptacles 
of farina, and in searching for these, ducks destroyed the 
plants occasionally. Calla palustris is a beautiful bog-plant, 
and I know nothing that produces a more pleasing effect over 
rich, soft, boggy ground. It will also grow by the side of 
water. Calla ethiopica, the well-known and beautiful Lily 
of the Nile, is hardy enough in some places if planted rather 
deep, and in nearly all it may be placed out for the summer; 
but, except in quiet waters, in the south of England and Ire- 
land, it will not thrive. However, as it isa plant so generally 
cultivated, it may be tried without loss in favourable positions. 
Pontederia cordata is a stout, firm-rooting, and perfectly hardy 
water-herb, with erect and distinct habit, and blue flowers, 
not difficult to obtain from botanic garden or nursery. The 
Sweet-flag will be associated with the Water Iris (I. Pseu- 
dacorus), and a number of exotic Irises will thrive in wet 
ground, ve. I. sibirica, ochreleuca, graminea, and many others. 
Aponogeton distachyon is a native of the Cape of Good Hope, 
a singularly pretty plant, which is hardy enough for our 
climate, and, from its sweetness and curious beauty, a most 
7 
