Marsilea (Water Clover)
Water clover is a deciduous, aquatic fern, bearing 4 parted leaf resembling 4-leaf clover. Producing clumps of leaves up to 15 to 20 cm tall at intervals, creeping, much-branched rhizome. Leaves floating in deep water or erect in shallow water or on land.
Each stalk bearing a single shamrock-like leaf with four wedge-shaped leaflets. The plant forms dense stands or has a random growing pattern. Sporocarp ellipsoid, long, dark brown. The plant has been harvested from the wild for local use as a food and medicine. It is often cultivated as an ornamental in aquaria and garden ponds.
However, differentiating between them is problematic without having the sexual reproductive structures, called sporocarps, which are formed in emersed conditions only. The growth patterns and appearance of the species widespread in aquariums are similar enough that determining the exact species is often not of great importance. Species commonly seen include M. crenata, M. hirsuta, M. quadrifolia, M. mutica and M. minuta. Less common are M. drummondii and M. angustifolia. The easiest species to differentiate in this group is M. minuta. With lush nutrients and high light, its leaves will be much smaller than those of the other species available. However, under more modest conditions, its appearance can be similar to the rest.
Marsilea species are relatively undemanding and can be grown in moderate lighting with a regular fertilizing regimen. Higher lighting and carbon dioxide injection improve growth rate and promote more compact growth.