Thursday, January 28, 2010

Common milfoil

Myriophyllum simulans
These must be some of the smallest flowers in my garden. (The leaves are 1cm long).
The belong to a little milfoil, one of the plants which would have been common in the swamps and waterholes of our district before white settlement.
These are fast-growing ornamental plants, much used in aquariums where light levels are high. Though native to Australia they have been exported to America, where they are sold as “frill foxtails” or “filigree myrio”. I hope they do the environment over there no harm. The same trade has introduced two horrors to Australia - the South American M. aquaticum and the Eurasian M. spicatum are two milfoils which should never have been allowed into Australia, where they are now invasive weeds, choking dams, rivers, and irrigation channels. There seems to be no excuse for it, when we have several attractive native milfoils which serve the purpose perfectly well, looking pretty in aquarioums and giving fish something to nibble on and somewhere for their babies to hide.

Milfoils are curious plants. They grow in still shallow freshwater, and during winter they live under it. They can only flower out of water, though, so when summer comes, they put up their heads, grow a different (simpler and tougher) kind of leaf, and pretend to be little Christmas trees. They produce their flowers - first the females, then the males higher up the stem. As their seeds begin to develop, they sink below the water again for the winter.

In the photo at right there are two stems from the same plant - one from underwater and one from above.

Like so many of our native plants, these milfoils are adapted to our unreliable climate. They can survive with the whole plant out of the water, provided the mud they grow in doesn’t dry out.
Most of the world’s Myriophyllums are native to Australia and China, where they are regarded as valuable food for pigs, ducks and fish. They are all medicinal plants, and have another unexpected use - for polishing wood.
They are also highly regarded as water-purifying plants. For this use, they should be harvested regularly. Removing the plants from the water is the final step in any water-purifying process.

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