From: ted.held at us.henkel.com (ted.held at us.henkel.com) on 2007.12.11 at 13:34:53(16802)
Dear List,
Let me summarize about what we know about transporting Lemna: You can
probably get away with just about anything and the Lemna will arrive
perfectly vigorous and ready to take over any body of still water in which
there are no carp.
My question is:What scientific inquiry was at the root of the original
request? I can't even remember now who it was who asked about it. Is there
some interesting experiment that is planned?
Lemna minor holds a special fascination for me as an aquarist and
aficionado of watery places. (So, too, the other (three?) floating aroids
that I know about.) These guys are unusually successful plants. They have
spread across the globe. Question: Were they always across the globe, or
were they inadvertently introduced from some original continent? They
thrive with (apparently) little or no sexual reproduction. Is that true?
Has anyone ever seen a Lemna flower or seed? Why are they not susceptible
to infection, being a single clone? They (especially Lemna) are very
hardy. I have collected pond-side muck and kept it in the dark for months
only to have new Lemna arise as soon as conditions permit. What is the
nature of a Lemna resting spore and what conditions can be endured by them
while maintaining viability? What induces a resting spore? Are resting
spores from Florida the same as the ones that overwinter here in Michigan?
The main problem I have with Lemna minor is that I can't get rid of them
easily. Scrupulous vigilance (or a 10-cent goldfish) will keep them down.
But if you leave even the tiniest remnant floating you'll have a carpet of
green in a couple of months. From an aquarist's point of view another
species, Spirodela polyrrhiza, is much more manageable, maybe because the
plants are individually larger. Despite this rampant vigor I have never
seen a flower in Lemna minor or in Spirodela.
My morning's idle speculation.
Ted.
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