Among the other water plants that grow rooted in soil and extendand to, or just above, the surface (sometimes described collectively as ‘deep marginals’, there are a few with qualities that make them welcome in the ornamental pool and one family, Nuphar, that includes some highly undesirable members.
Aponogeton distachyus. Deserves a place in every pool, large or small. Happy in any water depth from 4 to 18 in., its oval leaves float on the surface and theproject just above it. They are forked and lobed into a most intriguing shape, snow white with jet black anthers, and loaded with pervasive perfume. The heavy May-tree scent earns it the name of Water Hawthorn. It flowers abundantly in early summer and again in the autumn, and always has buds ready to unfold in any mild spell during the winter months. Shade tolerant.
Nuphar advenum and Nuphar luteum. These are, respectively, the Yellow Pond Lilies of North America and Europe. They will tolerate shade, cold currents and deep water (up to 6 or 8 ft. even) but they are too invasive and indestructible, their leaves too large and their flowers too small, for them to be of use in any situation where nymphaea could be grown instead.
Nuphar minimum (pumilum). Reputed to be a well-behaved miniature form, with tiny leaves and 1-in. Bright yellow flowers, suitable for small pools and shallow margins.
Orontium aquaticum. Will make itself at home anywhere from a muddy pool margin down to a water depth of 18 in. The very attractive velvety, silvered blue-green leaves grow 12 in. or more high or float on the surface according to the situation. The numerous white-stemmed flower spikes, densely crowded with tiny yellow flowers, give it the name Golden Club.
Villarsia nymphaeoides (Water Fringe). Has suffered a good deal over the years from name changing; its current legitimate title is Nymphoides peltata. It is a dainty little plant, very like a small, with 2-in. Mottled heart-shaped leaves and bright yellow poppy flowers lifted above the surface. From 4 to 18 in. of water suit it, and it is capable of colonising rapidly and permanently any shallow area with a muddy bottom.