Mime-Version: |
1.0 (Apple Message framework v930.3) |
Content-Type: |
text/plain; charset=US-ASCII; format=flowed; delsp=yes |
Date: |
Tue, 12 May 2009 08:51:51 -0400 |
Reply-To: |
|
Subject: |
|
From: |
|
In-Reply-To: |
|
Content-Transfer-Encoding: |
7bit |
Sender: |
|
Parts/Attachments: |
|
|
On May 12, 2009, at 12:00 AM, BEE-L automatic digest system wrote:
> [log in to unmask]
The american elm
Having done my graduate work on Dutch Elm Disease I've spent about
8 years in elm tree canopies around the NE. The monumental Mall in
the capital was/is surrounded by American Elms. I have not been there
for 20 years.
Elms flower early in the year, I have a siberian in my back yard
that is raising seed now. The Elms tend to seed prior to leaving so
it is an early (upstate NY) source for pollen--I believe it to be low
quality. It is not a nectar source as the Ulmaceae does not have
floral nectaries. The tree is normally a wind pollinated species and
may be an emergency alternate source of pollen in the spring.
CAUTION: The Dutch Elm Disease has evolved a more virulent form
that is capable of taking down some of the "resistant" cultivars. The
other major disease that assisted the depletion of the American Elm
was a (introduced) pathogen that is vectored by a flugorid (flying
leaf sucking insect) called Elm Yellows--a Phytoplasm!
I love American Elm but not sure they will ever recover the majesty
they once held in American cities!
Mike
Dutch Elm Disease was very very good to me--paid my graduate education!
***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html
|
|
|