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Mangrove
ferns
Acrostichum sp.
Family Pteridaceae
updated
Aug 09
Where seen? These ferns are often seen in back mangroves,
flourishing on mud
lobster mounds and other higher ground. Elsewhere, they naturally
occur in tidal swamps, muddy coasts, river banks and tidal estuaries.
They can be common and even dominant in the understorey of back mangroves.
'Piai' means 'shrimp' in Malay, and this may be because these
ferns grow well on raised bunds created for shrimp farming. Another
malay name for them is 'Paku Laut' which means 'Fern of the
Sea'.
Features: Fronds green, long and
narrow. Like other ferns, they do not produce flowers or fruits. Instead,
they reproduce through spores. In fertile fronds, all or only the
leaflet tips are brown with spores. There are two species of mangrove
ferns in our mangroves: Piai raya (Acrostichum
aureum) and Piai lasa (Acrostichum
speciosum). Below is more on how to tell them apart.
Role in the habitat: Among the
first large low-growing plants to grow on the landward side of the
mangrove, the ferns provide shade for other plants and trees to take
root. But in cleared mangroves, the ferns can take over so rapidly
that they form impenetrable thickets which prevent other plants from
taking root. Thus it is often considered a weed. For animals, these
thickets provide safety and shelter and for birds to nest.
Human
uses: According to Burkill, the young leaves are eaten
in Borneo, the Celebes and Timor. Medical uses including placing pounded
or grated rhizomes as a paste on wounds and boils in Malaya and Borneo.
In some parts of our region, the leaves are dried and used as thatching
which is considered superior because they last longer. And should
they catch fire, they burn so quickly into ash that the fire is not
sustained to endanger any other parts of the home. |

Sungei Buloh
Wetland Reserve, Mar 09

Sungei Buloh
Wetland Reserve, Jan 04
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Larger plant with longer fronds.
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Young fronds are red.
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Sterile leaves have blunt tips,
sometimes with a small point.
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Smaller plant with shorter fronds.
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Young fronds are green.
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Sterile fronds have pointed tips.
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