Marsilea crenata

The Dwarf waterclover, Marsilea crenata, is a pretty aquatic fern from tropical Asia and Australia that forms a small-leaved carpet in the aquarium. M. crenata is also sometimes regarded as a synonym of Marsilea minuta and is labelled as such by the company Tropica, for example. Like other Marsilea species, this fern grows in nature in various wetlands such as swamps, rice fields and floodplains. In the terrestrial form, long-stalked leaves with four leaflets grow on the creeping rhizomes, looking like "lucky clover". Marsilea crenata is usually sold in this emersed form.
After some acclimatisation time, new shoots with much shorter submerged leaves grow in the aquarium, while the old emersed leaves slowly die off and can be cut off. The submerged leaves are usually undivided with small, rounded to spatulate leaf blades and are rarely more than 5 mm wide. They are significantly smaller than the submersed leaves of Marsilea hirsuta. Sometimes two-, three- or four-part leaves of different heights develop. Marsilea crenata spreads moderately quickly in the aquarium with its runners. The carpet grows to a height of about 1 - 3 cm.

Marsilea crenata is a robust aquarium plant and can cope with relatively little light; the CO₂ requirement is also low. However, the Dwarf waterclover develops best with at least moderate light and a complete supply of nutrients, including via the substrate, and the addition of CO₂.
After removing the rockwool, it is best to divide emersed potted plants into several pieces and place them in the substrate at some distance from each other. When rhizome shoots with submerged leaves develop, the old emersed leaves gradually die off and can be cut off. Tissue-cultured plants are also divided into several pieces and planted after washing off the culture medium.
Over time, the rhizomes creeping in the soil or above ground grow together to form a carpet. Occasional cutting prevents the carpet from becoming too thick and eventually detaching from the ground. Propagation is easy by cutting off pieces of rhizome and sticking them in the ground.

Particularly in Marsilea from in vitro (tissue culture) cups, new leaves have a brownish colour. They are by no means rotten.

The Dwarf waterclover is a relatively undemanding, versatile ground cover that requires little light. With its moderate growth rate, it is easier to manage than Glossostigma elatinoides, for example. Marsilea crenata, with its leaves that are significantly smaller than those of the Rough waterclover (Marsilea hirsuta), is well suited to small or nano aquariums. In its emersed form, this fern, which looks like "lucky clover", makes a pretty accent in paludariums and wabi-kusa.