Date: Fri, 04 Aug 2000 10:50:44 -0700 From: chamb@u.arizona.edu To: cp@opus.hpl.hp.com Message-Id: <aabcdefg2360$foo@default> Subject: Re: U. inflata as weed
At 08:54 AM 8/4/2000 -0700, you wrote:
>But then you'd have to explain why it is that U. inflata
>(which would seem to be a master of bird-travel) is not scattered
>throughout nearly every wetland on the eastern side of the state. Even if
>plants couldn't survive a winter, surely each spring the vast numbers of
>northward-bound migrating birds would be dragging U. inflata all the way
>up to the Great Lakes area. But they aren't.
Some plants being called Utricularia inflata do occur in the Great Lakes
region, where they are rare and localized in a few populations in SW
Michigan and adjacent Indiana. Utricularia inflata is on the list of
Michigan endangered species:
http://www.michbotclub.org/plants_mich/endangered.htm
However, there has been widespread confusion in the use of the names U.
inflata and U. radiata, no doubt in part due to the latter being sometimes
treated as U. inflata var. radiata. The Michigan and Indiana plants are
actually Utricularia radiata as treated in Taylor's Utricularia monograph.
These blatterworts are believed to be native in this area. Many marshes
and fens at the southern end of Lake Michigan are home to a surprising
number of plant species disjunct from the US eastern coastal plain. Most
of these plants are Cyperaceae, but some more conspicuous plants, such as
Rhexia virginica and R. mariana, and U. radiata and U. subulata also share
this distribution pattern.
In spite of the widespread use of recreational floatation devices, such as
boats, in the Great Lakes region, I'm not aware of any introductions of
exotic Utricularia in Michigan or neighboring states. Other weedy aquatics
are a different story...
For unparalleled fun with weeds in the water, query North American
nonindigenous aquatic vascular plants by drainage region at this web site!:
http://nas.er.usgs.gov/plants/huc6_us.html
Michael
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