Marsilea hirsuta

Marsilea hirsuta is a fascinating plant, usually delivered with leaves like a four-leaf clover. After a transitional period it develops different types of leaves, possibly a low form with single leaves like a large Glossostigma, or alternatively develop two, three or four-lobed leaves varying in height, depending on the growth conditions. Whichever form the plant adopts, it forms runners and spreads rapidly round the aquarium. The scientific name for this unusual aquatic fern has not yet been finally settled.