There are about 400 species, but only a few are grown as houseplants. However. these are of considerable merit, and very attractive as foliage plants.
Popular Species
Pilea cadierei (Aluminium plant)
A great favorite is P. cadierei, the aluminium plant. It is extremely neat in the form P. C. nana, which is usually sold as a houscplant. and grows only 30cm (lit) high. It makes a compact, bushy little plant with very pretty silver-blotched rich-green spear-shaped foliage. It is native to Vietnam. In cultivation it tends to suffer from magnesium deficiency, to which it appears extra sensitive. If this happens the leaves may become distorted and pale, losing their contrasting colours. It is a wise precaution to water from time to time with a solution of Epsom salts – 5ml (1 teaspoon) to 500ml (1 pint) of water.
Pilea microphylla (Artillery plant)
P. microphylla (syn. P. muscosa), the artillery plant or gunpowder plant, is absolutely different in appearance, forming a neat, bushy plant with delicate ferny foliage. From May to September. inconspicuous greenish-yellow flowers are produced. These, on the slightest disturbance, issue clouds of pollen from their anthers, looking like puffs of yellow smoke and suggesting the common name.
It comes from tropical America, and is easy and seems happy with quite cool conditions.
Pilea involucrata (Friendship plant)
P. involucrata. the friendship plant, is from Peru and Venezuela, and is a low and slow-growing plant with leaves of similar shape to P. cadierel. The oval leaves are slightly hairy, and much corrugated, purplish below and bronzy-green above. There is some confusion with this plant, often being mistaken for P. spruceana.
Pilea nummulariifolia (Creeping Charlie)
P. ninnnnilariifolia, creeping Charlie, is a dainty creeper, useful for hanging pots or baskets. It has wiry, reddish stems. bearing small, corrugated heart-shaped leaves. It comes from South America.
Pilea mollis (Moon valley plant)
P. mollis, the moon valley plant, is easy to grow from seed. It has spear-shaped, yellowish-green crinkled foliage, with contrasting darker green veining. It can be raised from spring sowings on a window-sill.
Cultivation & Care
The pileas grow easily in most potting composts, and generally 13cm (5in) pots are suitable. In winter, a position in good light should be found, but slight shade is necessary at other times. At all times, maintain a moist compost. giving more water in summer when active growth is being made.
Propagation & Maintenance
If grown for too long, the plants become leggy or deteriorate. They are best propagated from cuttings every three or four years. The best time for potting is spring, and at this time any trimming or pruning should be done.
In cold, damp conditions. where the air is stagnant, grey mould fungus may attack, particularly affecting P. cadierei, the central stems at the base of the clump being most affected. The most likely pest is aphids. but these are easy to control.