The water clover Marsilea hirsuta is widely spread in Australia. It is mostly found in marshes and floodplains.
In trade, you often see the names M. crenata, M. hirsuta, M. exarata, M. drummondii and M. quadrifolia, however, it is not sure whether the respective plant was identified correctly. Most species of the genus Marsilea can only safely be identified in their emersed form by means of their sporocarps (spore-containing fruit).
Please see Marsilea spp.
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