Pilea cadierei: Aluminium Plant, Friendship Plant
The nettle family includes many attractive genera that can be used for gardening purposes. In all botanical gardens (often also in rock gardens) one will find Helxine soleirolii, a pretty prostrate plant with small, dense leaves that is sometimes used as a substitute for turf. Also frequently cultivated are the ornamental species of the genera Boehmeria, Debregeasia, Laportea and Pellionia. Most widely used in homes, however, is the genus Pilea, comprising some 200 species distributed in the tropics on all continents excepting Australia.
Pilea cadierei is native to the tropical rain forests of Indochina (reference books often say Africa, more specifically the Congo, but this is probably a mistake). It grows to a maximum height of 40 cm (16 in), but is usually shorter. The leaves, marked with large silvery patches (hence the name aluminium plant) are almost 10 cm (4 in) long.
Another commonly cultivated species is P. microphylla from the South American Andes, where it grows up to elevations of 2,000 m (6,600 ft). It is a small herbaceous plant with tiny leaves up to 0.5 cm (’/4 in) long at the most, which often grows on stone walls and rocks and is the only member of the genus that tolerates direct sun. P. spruceana from the region between Venezuela and Peru has brownish-red leaves covered with blister-like growths. More often grown are its cultivars, ‘Norfolk’ and ‘Silver Tree’, both lovely, small, variegated plants.
Most species grow in the bottom layer of rain forests and even though they prefer places with more light, such as stones in stream beds and the banks of streams, they will tolerate only diffused light. They are very good subjects for a demijohn or a plant-case. The compost should be a mixture of peat, sand and loam. Propagation is easy; cuttings root readily even in water.