Subject: Re: pernicious plants
Date: Feb 17 14:23:06 1995
From: Eugene Hunn - hunn at u.washington.edu


I know it is commonly asserted the reed canary grass is introduced, but
as I recall Hitchcock and Cronquist were not explicit on that point.
What is the evidence.

Gene Hunn.

On Fri, 17 Feb 1995, Dennis Paulson wrote:

> That was a good list, Don, with good information; thanks. I would add
> PURPLE LOOSESTRIFE to the list without hesitation, as it doesn't seem to do
> much good for any wildlife and renders a lot of harm by choking out other
> more productive marsh vegetation (not to mention eliminating shorebirds
> from Montlake Fill, for which it has my personal animosity--but then again,
> the people who manage the fill could have managed to eliminate the
> loosestrife if they were so inclined).
>
> It's clear that there are hundreds of weedy species that effect relatively
> minor changes on ecosystems, but the ones named have the unpleasant
> propensity to take over large stretches of (often disturbed) habitat by
> successfully outcompeting native and other weedy species, and, for the most
> part, they don't have much value to wildlife. Himalayan blackberry
> probably is an exception to this, as it furnishes habitat for a lot of
> thicket-inhabiting small birds and mammals, and the fruits are eaten by
> quite a few species. It's more of a bother to humans than are some of the
> others; EURASIAN WATERMILFOIL is a tremendous bother to humans but is used
> by a lot of waterfowl; where it gets extremely dense it does choke out
> other aquatic vegetation and open-water species of fish and birds.
>
> We definitely should distinguish weeds that are damaging to natural
> ecosystems from weeds that are inconveniencing to us. I think bracken
> would only fit in the latter category, if at all. As would Russian
> thistle, Canada and bull thistles, and some other species. At least we
> don't have pernicious TREES, as do many areas of the tropics.
>
> Dennis Paulson, Director phone: (206) 756-3798
> Slater Museum of Natural History fax: (206) 756-3352
> University of Puget Sound e-mail: dpaulson at ups.edu
> Tacoma, WA 98416
>
>
>