# Marsilea

Marsilea is a genus of approximately 65 species of aquatic ferns of the family Marsileaceae. The name honours Italian naturalist Luigi Ferdinando Marsili (1656–1730).
These small plants are of unusual appearance and do not resemble common ferns. Common names include water clover and four-leaf clover because of the long-stalked leaves have four clover-like lobes and are either present above water or submerged. It is worth clarifying that these plants are not clovers.
The sporocarps of some Australian species are very drought-resistant, surviving up to 100 years in dry conditions. On wetting, the gelatinous interior of the sporocarp swells, splitting it and releasing a worm-like mass that carries sori, eventually leading to germination of spores and fertilization.

## Uses
### As food

Sporocarps of some Australian species such as Marsilea drummondii are edible and have been eaten by Aborigines and early white settlers, who knew it under the name ngardu or nardoo. Parts of Marsilea drummondii contain an enzyme which destroys thiamine (vitamin B$_1$), leading to brain damage in sheep and horses. During floods in the Gwydir River basin 2,200 sheep died after eating nardoo. Three-quarters of the sheep that were affected did however respond to thiamine injections. Thiamine deficiency from incorrectly prepared nardoo likely resulted in the starvation and death of Burke and Wills.
The leaves of Marsilea crenata are part of the East Javanese cuisine of Indonesia, especially in the city of Surabaya. It is called Pecel Semanggi and is served with spicy peanut and sweet potato sauce.

### Ornamental

A few species in the genus, such as Marsilea crenata, Marsilea exarata, Marsilea hirsuta, and Marsilea quadrifolia, are grown in aquaria.

### Formerly placed here

* Salvinia natans (L.) All. (as M. natans L.)

## Phylogeny

Molecular phylogenetic analysis of the genus Marsilea shows the following tree. This tree indicates that M. crenata is the same species (or a subspecies) of M. minuta, and possibly M. fadeniana also. Additionally, this analysis contradicts reports that M. polycarpa is a synonym for M. minuta
| Nagalingum et al. 2007 | Fern Tree of Life |
| Group I Clemys M. crotophora M. polycarpa subgroup Mutica M. mutica subgroup Group II Macrocarpa M. aegyptiatica M. botryocarpa M. ephippiocarpa M. farinosa M. macrocarpa M. schelpiana M. vera M. villifolia subgroup Nubica M. nubica (Botswana) M. nubica (Nigeria) subgroup Capensis M. distorta M. capensis M. gibba subgroup Nodorhizae M. ancyclopoda M. macropoda M. nashii (Grand Turk Island) M. nashii (West Indies) M. oligospora M. vestita M. villosa M. mollis subgroup Marsilea M. angustifolia M. drummondii M. minuta‑crenata‑ M. crenata (Indonesia) M. crenata (Thailand) M. minuta (India) M. minuta (Myanmar) M. minuta (Africa) M. fadeniana fadeniana complex M. quadrifolia subgroup | section M. mutica Mett. (Large-leaved nardoo) M. scalaripes D.M. Johnson M. crotophora D.M. Johnson M. deflexa A.Braun M. polycarpa Hooker & Greville Clemys section M. mollis B.L. Rob. & Fernald (Chihuahuan water clover) M. ancyclopoda A.Braun (Tropical Water Clover) M. macropoda Engelm. ex A.Braun (Bigfoot water clover) M. nashii Underwood M. villosa Kaulf. (ʻIhiʻihi) (Hawaii) (ʻIhiʻihi) M. oligospora Goodd. M. vestita Hook. & Grev. (Hairy Water Clover) Nodorhizae M. macrocarpa M. schelpeana Launert M. owambo Doweld M. villifolia Brem. & Oberm. ex Alston & Schelpe M. aegyptica Willd. M. ephippiocarpa Alston M. botryocarpa Ballard M. farinosa Launert M. macrocarpa C.Presl species‑group section M. nubica A.Braun M. capensis A.Braun M. gibba Brown M. coromandelina Willd. M. distorta A.Braun M. quadrifolia L. (European Water Clover) M. fadeniana Launert M. crenata C.Presl M. minuta L. (Dwarf Water Clover) M. strigosa Willdenow M. drummondii A.Braun (Common Nardoo) M. hirsuta R. Br. (Rough water clover) M. exarata Brown M. costulifera Jones M. angustifolia Brown M. azorica Launert & Paiva Marsilea |
Other species include:
* Marsilea aethiopica Launert
* Marsilea apposita Launert
* Marsilea batardae Launen
* Marsilea burchellii A.Braun
* Marsilea condensata Bak.
* Marsilea cryptocarpa Albr. & Chinnock
* Marsilea fenestrata Launert
* Marsilea globulosa Bouchart
* Marsilea hickenii Herter
* Marsilea latzii Jones
* Marsilea megalomanica Launert
* Marsilea pyriformis Bouchart
* Marsilea quadrata Brown
* Marsilea ×subangulata Brown
* Marsilea subterranea Leprieur
* Marsilea unicornis Launert
* Marsilea vera Launert