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Common Name: Smooth Nardoo

General Information

Marsilea mutica is a Fern up to 0.90 metres tall.
It is harvested from the wild for local use as a food.

Known Hazards

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable[].
The sporocarps of this species also contain thiaminase, an enzyme that robs the body of vitamin B1. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. Fairly resistant to heat, the quantity of enzyme can be greatly reduced by thoroughly drying or cooking the plant[, ].

Botanical References

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Range

Australia - Queensland, New South Wales, Western Australia, southern Tasmania, Northern Territories

Habitat

Edges of ponds and lagoons, on river banks and in deep water[]. Shallow water in seasonally wet habitats[].

Properties

Edibility Rating
Habit	Fern
Height	0.90 m
Cultivation Status	Wild

Cultivation Details

We have very little information on this species, and do not know if it will be hardy when grown outdoors in Britain, though judging by the plants native range, there is a good chance that forms from the south of its range could prove hardy at least in the milder areas of Britain.
Most species produce sporocarps as their habitat dries. Spores of some species retain viability within the sporocarp for nearly 70 years; thus species can survive in areas of infrequent rainfall[].

Edible Uses

Spores - cooked[]. A source of starch, the spores can be ground into a powder and used like flour. They are astringent and highly indigestible. The spores are contained in a sporocarp.The sporocarps are a rich source of thiaminase, an enzyme that can destroy vitamin B1 in the diet[]. As such, they are best viewed as a temporary food of last resort[].

Medicinal

None known

Other Uses

None known

Propagation

Spores. The plant produces sporocarps, these need to be lightly abraded and then immersed in water. The sporocarps will then swell and burst to release the spores. The spores germinate immediately, the highly developed prothallus remains inside the large seed-like spores. The gametophyte generation is completed in 24 hours and the first roots and shoots appear in 2 - 3 days. Mature plants bearing sporocarps can develop in as little as 3 months[].
Spore germination in the family occurs after rupture of the sporocarp wall allows the sporocarp contents to be hydrated. A gelatinous structure emerges from the sporocarp, breaking it into valves and carrying the sori into the water. Spore germination (gametophyte growth) and fertilization occur immediately[].
Division.