Marsilea

Marsilea
File:Starr 061108-9797 Marsilea villosa.jpg
Marsilea villosa
Scientific classification
Kingdom:	Plantae
Division:	Pteridophyta
Class:	Polypodiopsida /  Pteridopsida (disputed)
Order:	Salviniales
Family:	Marsileaceae
Genus:	Marsilea L.
Species
See text.
Synonyms
Lemma Juss. ex Adans. Spheroidea Dulac Zaluzianskia Neck.

Marsilea is a genus of approximately 65 species of aquatic ferns of the family Marsileaceae. The name honours Italian naturalist Luigi Ferdinando Marsigli (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 the long-stalked leaves have four clover-like lobes and are either held above water or submerged.

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

File:Marsilea azorica (Habitus).jpg

Marsilea hirsuta was introduced to the Azores but formerly thought to be an endemic species, M. azorica

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 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 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.

Selected species

Marsilea aegyptiaca Marsilea ancyclopoda A.Braun – Tropical Water Clover Marsilea crenata C.Presl Marsilea drummondii A.Braun Marsilea exarata A.Braun Marsilea hirsuta R.Br. – Rough Water Clover, (incl. Marsilea azorica Launert & Paiva) Marsilea macropoda Engelm. ex A.Braun – Bigfoot Water Clover

Marsilea minuta L. – Dwarf Water Clover Marsilea mollis B.L.Rob. & Fernald – Chihuahuan Water Clover Marsilea oligospora Gooding – Pacific Water Clover Marsilea polycarpa Hook. & Grev. – Guyanan Water Clover Marsilea quadrifolia L. – European Water Clover Marsilea vestita Hook. & Grev. – Hairy Water Clover Marsilea villosa Kaulf. – ʻIhiʻihi (Hawaii)

Formerly placed here

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

See also

• Bush bread

References

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