This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
In some districts, where the Yellow Water-lily floats on the bosom of ponds and sluggish streams, it is known as the Brandy-bottle, partly by reason of its unpleasant odour and partly on account of its flagon-like seed-vessel.
It has a thick fleshy rootstock, which creeps in the mud, and is rich in tannic acid; it is said to be a fatal lure to cockroaches if bruised and soaked in milk. Some of the leaves are submerged, and these are thin, but the floating ones are thick and leathery. The leaves are heart-shaped, the lobes not far apart; the stalks somewhat triangular in section, and traversed by a great number of fine air-canals, as are the flower-stalks also. The most conspicuous portion of the flower is the sepals, five or six in number, which are very large and concave. The petals are much smaller, and number about twenty; they produce honey at their base. The stamens are even more numerous than the petals, in several rows, their blunt tips bent over away from the many-celled ovary. The stigma is rayed. The fruit ripens above water, and is, as we have indicated, flagon-shaped; the seeds are imbedded in pulp. Flowers from June till August.
There is another species:The Lesser Yellow Water-lily (N. pumilum), which occurs in Shropshire and in Scotland, from Elgin to Argyll, but it is rare. Its oblong leaves are divided at the base, the lobes becoming distant from each other. The petals are rounder than in luteum, the anthers shorter, and the rays of the stigma reach to the margin, which is lobed.
The name is from the Arabic for this or a similar plant, naufar.
The White Water-lily (Nymphaea alba), though constituting the British representative of a distinct genus, is closely allied, as, indeed, is the magnificent Victoria regia of South American rivers, with leaves 10 or 12 feet across, and flowers 15 inches and more in diameter.