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Old 26-04-2003, 01:30 PM
Sean Houtman
 
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Default Primary function of awn in Poaceae

From: (Phred)

But if we're talking *dispersal* then that's another matter, and I'm
not sure what help the awns would be in that sense -- except perhaps
mechanical entangling in hair, fur, or feathers. (But I can say that
the seeds of black spear grass [_Heteropogon contortus_] don't need
the *awns* to become painfully embedded in your flesh! The hairs on
the tip of the "seed" seem to do the job quite well enough if they've
got a bit of purchase on something like your socks. And some of the
three-awn spear grasses [_Aristida_ spp.] are worse! )


If you would like to see how awns can help disperse seed without tangling in
fur, get a spike of wheat or barley (use one of the awned varieties of course),
and let it roll across your hand. The awns pretty much make sure that the spike
tends to move in one direction.

Sean



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