Several species of aquatic plants do well when planted in ponds and other waters throughout the metropolis, and the beauty of these in several of the lakes in the London parks testify to how well suited they are for town planting.

Cape Pond Weed (Aponogeton Distachyon)

One of the best is the Cape Pond Weed (Aponogeton distachyon), which not only flowers freely but reproduces itself from seed. The sweetly scented large white flowers with dark anthers are both conspicuous and ornamental.

The Flowering Rush (Butomus umbellatus)

The Flowering Rush (Butomus umbellatus) thrives vigorously in several ponds in smoky parts of London and may be considered a most desirable plant for such positions. It should be planted by the water margin. Menyanthes trifoliata (the Bog Bean) has become quite established in several waters in the metropolis, and its white horsechestnut-like flowers make it a general favourite. It is of stout growth and does well where the water is shallow. Perhaps one of the showiest of aquatic plants is the Double Flowered Arrow Head (Sagittaria japonica fl. pl.), which is of stout growth with arrow-shaped leaves and immense double white flowers. It is a gem for the town lake or pond. All the species of Typha do exceedingly well in shallow water and add quite a charm to the pond or lake side. T. minima is especially suitable where the extent of water is small.

Water Plants In London. To face page 168.

The Water Violet (Hottonia palustris)

The Water Violet (Hottonia palustris) with its submerged fern-like leaves and snowy white flowers is another desirable aquatic plant; which may also be said of Villarsia Nymphaeoides, both excellent species where the air is impure.

Of Water Lilies

Of Water Lilies many species would appear to do well, and the common yellow and white have succeeded in London waters for many years. Some of Marliac's varieties also do well and are extremely showy, preferably the red and yellow forms. It might be mentioned that the Cape Pond Weed and one of Marliac's pink Water Lilies have succeeded well for the past ten years in a small pond in the very heart of London. Of course, when the water is renewed at frequent intervals aquatic plants have a much better chance of succeeding than when this is stagnant, and especially if polluted by soot and other atmospheric impurities.