Geogenanthus ciliatus aka Midnight Silk

Geogenanthus ciliatus is a low herb that lives for years. It belongs to the Commelinaceae family. Its home range runs from Ecuador into northern Peru. It grows on the ground in primary rain forest. Kew places it in the wet tropical climate zone. It is a forest herb, not a woody shrub. People grow it for its looks. They also gather wild plants for use in local medicine. The RHS confirms it is not native to Britain or Ireland.

The plant forms a mat about 0.5 feet (0.15 metres) tall. Its round leaves measure about 0.5 feet (0.15 metres) across. The deep purple leaves are its main point of garden interest. Broad leaves and low growth suit its use as ground cover. The account gives no mature width or growth rate. It gives no details of stems, flowers, or fruit. The sources name no bloom season, so its timing remains unclear.

When grown in gardens, it needs moderate or deeper shade. It prefers soil rich in humus that stays moist but drains well. Both moist soil and good drainage are among its stated needs. The sources give no watering schedule or soil pH. Its tropical home does not tell us its exact cold limit. The sources give neither a USDA zone nor a UK hardiness rating. They list seeds and stem cuttings as ways to raise new plants.

Its recorded role in gardens is as a low ground cover. The purple leaves bring colour close to the soil surface. Useful Tropical Plants notes use for looks and collection from the wild. It names no garden forms and gives no guide to spacing. The sources report no pests or diseases for this species. This lack of reports does not mean it resists either. Nor do they show how hard it is to grow.

Useful Tropical Plants lists no known food use or known hazard. This does not prove that the plant is safe to eat. The account records several local uses as medicine, not tested treatments. One practice puts a boiled mix on swollen knees. Another gives infants a mix made with cold water for worms. A further practice uses a leaf for relief from wind. These reports show past use, not proven benefit or safe doses.