''Marsilea'' is a genus of approximately 65 species of aquatic

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

s 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 Clovers, also called trefoils, are plants of the genus ''Trifolium'' (), consisting of about 300 species of flowering plants in the legume family Fabaceae originating in Europe. The genus has a cosmopolitan distribution with the highest diversit ...

-like lobes and are either present above water or submerged. It is worth clarifying that these plants are not clovers. The sporocarps of some

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n 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

spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s 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 An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

which destroys

thiamine Thiamine, also known as thiamin and vitamin B1, is a vitamin – an Nutrient#Micronutrients, essential micronutrient for humans and animals. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosp ...

(vitamin B₁), 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 Thiamine, also known as thiamin and vitamin B1, is a vitamin – an Nutrient#Micronutrients, essential micronutrient for humans and animals. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosp ...

deficiency from incorrectly prepared nardoo likely resulted in the starvation and death of

Burke and Wills The Burke and Wills expedition (originally called the Victorian Exploring Expedition) was an exploration expedition organised by the Royal Society of Victoria (RSV) in Australia in 1860–61. The exploration party initially consisted of nine ...

. The leaves of '' Marsilea crenata'' are part of the East Javanese cuisine of

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

, especially in the city of

Surabaya Surabaya is the capital city of East Java Provinces of Indonesia, province and the List of Indonesian cities by population, second-largest city in Indonesia, after Jakarta. Located on the northeastern corner of Java island, on the Madura Strai ...

. 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 In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

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 reportsTropicos.org. Missouri Botanical Garden. 25 Sep 2017 http://www.tropicos.org/Name/26602149 that '' M. polycarpa'' is a synonym for ''M. minuta'' 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

References

*Mabberley, D.J. (1997). ''The Plant-Book''. Cambridge University Press. * Edmund Russow: ''Histologie und Entwicklungsgeschichte der Sporenfrucht von Marsilia.'' Dissertation. Dorpat 1871
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*Johnson 1986 Systematics of the New World species of Marsilea. Syst. Bot. Monog. 11:1–87.

* {{Authority control Aquatic plants Fern genera ja:デンジソウ