grasses and gondwana
kinman at HOTMAIL.COM
Fri Jun 21 19:43:08 CDT 2002
Thanks. I will certainly look forward to Bremer's upcoming paper. I
wonder if there has been much work on searching for phytoliths of Poales in
the Upper Cretaceous of Australia (or Argentina)?
By the way, the content of Poales (sensu lato) seems to be pretty much
equivalent to Glumiflorae. Are the "glumes" what give rise to the phrase
I assume their tendency to "wind pollinate" must have helped Poales
spread back into devastasted areas following K-T (at least more quickly than
angiosperms which depended on animals to pollinate them). Or would
horizontal stems been more of a factor (especially with worldwide forest
fires at K-T)? No wonder grasses have done so well in the Cenozoic,
especially those which developed lots of herbivore-deterent phytoliths.
P.S. Sorry, I just can't resist asking. If flowers "orientate" toward the
sun in the morning, do they then "occidentate" later in the day? Egad,
that would sound just like "oxyidentate" (which sounds like it could be a
tooth-whitening product). :-)
>From: Peter Stevens <peter.stevens at MOBOT.ORG>
>To: TAXACOM at USOBI.ORG
>Subject: Re: grasses and gondwana
>Date: Thu, 20 Jun 2002 07:39:27 -0400
Kare Bremer has a paper coming out soon in
>>Evolution which will help a lot in clarifying phylogeny adjacent to
>>Poaceae. Anomochlooideae, sister to rest of Poaceae, are S.
>>American, sister to Poaceae itself is a small Australian family
>>(Bremer's finding), sister to the two... - and so on. It has indeed
>>been evident for quite some time that the members of the clade in
>>which Poaceae are situated are predominantly southern, a couple more
>>or less Malesian-Pacific.
>> Following up on my last post. It is interesting that some of the
>>closest relatives of true grasses (Poaceae) seem to be "graminoids" like
>>Restionaceae which seem to be southern forms.
>> Could the true grasses and close relatives perhaps have been more
>>widespread than we previously realized (especially in the southern
>>hemisphere) during the Cretaceous?
>> Any botanical biogeographers out there who could fill me in on this?
>>Perhaps gondwanatheres and early grasses evolved together in some way?
>> ------ Thanks, Ken
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