Cyperus alternifolius: Umbrella Plant
Plants of the Cyperaceae family are well known to everyone and not only to those who grow house plants. Take, for instance, the common sedges. In most cases these are wrongly mistaken for grasses with which they have little in common, apart from appearance. They are more closely related to the rushes (Juncaceae) and are an offshoot of the lily family.
The genus Cyperus is a very large one, comprising some 400 species distributed mostly in the tropical and subtropical regions. They are practically always found close to water, though some are xerophilous.
The Cyperus alternifolius is from Madagascar, where it forms almost impenetrable growths on the shores of lakes and water courses. In cultivation it generally reaches a height of 50 to 100 cm (20 to 40 ft) and will form dense clumps if its needs are satisfied.
In the home it may be grown beside or in the shallow water in a paludarium placed in a warm room. The compost must be sufficiently nourishing, composed, for example, of loam mixed with rotted turves, sand and some peat. Alternatively, use John Innes potting compost No. 1. The surface should be covered with a thick layer of sand. The temperature need not be reduced in winter.
Better suited for small pools are Cyperus haspan, which is relatively small (50 cm [20 in] at the most) with stems terminated by a thick ‘ball’ of narrow leaves; or C. hatalensis. For a large pool use can be made of the classic Cyperus papyrus, the famous plant of ancient Egypt, which grows to a height of 2 to 5 m (6 to 16 ft).
Propagation is not difficult. The plants may be divided when they are moved (but they should be moved as little as possible as they will form nice clumps only if left undisturbed) or by cutting off the terminal rosette of leaves together with a piece of stem about 1 cm (Va in) long and placing it either on the surface of water or in a muddy compost in a warm propagator, where it will soon form roots.