[APWG] Jewelweed

[Wayne Vanderploeg]

Hello All, 

I don't usually make comment to this group....I generally browse this list to 
see what new issues are popping up.  As a biologist/ecologist/naturalist/land 
manager for 31 years in the Chicago area with the Forest Preserve District of 
Cook County, I have seen this plant come and go.  Deer do browse it heavily and 
tend to prefer it over most other plants.  It does well in disturbed areas where 
the soil is rich, moist and semi shaded.  I have always viewed it as sensitive 
plant that is easily displaced by weeds and never thought of it as a problem 
plant in the Chicago area.  The fact that it is spreading prolifically in other 
areas where it typically does not occur could be a symptom of a bigger problem.  
I would expect it to disappear when those problems are discovered and solved.  


Wayne Vanderploeg




________________________________
From: "Maze, Dominic" <Dominic.Maze at portlandoregon.gov>
To: Katie Fite <katie at westernwatersheds.org>; "apwg at lists.plantconservation.org" 
<apwg at lists.plantconservation.org>
Sent: Tue, July 19, 2011 11:42:18 AM
Subject: Re: [APWG] Jewelweed

Jewelweed  
Hi Katie et alia,
   Impatiens capensis is, in my experience, a problematic species here west of 
the Cascade Range in the Pacific NW.  The densities of this sp. are pretty 
amazing with the understory of riparian corridors often dominated by it.  I’ve 
been seeing more and more of it in the Willamette  Valley and surrounding ranges 
here in  Oregon with seemingly little attention paid to it.
   Interestingly, some land managers still consider this species native here on 
the West Coast, probably due to confusion with our native, I.ecalcarata in some 
older floras and field guides.  Ed Alverson of TNC wrote a short comment in 
reply to a posting on I.capensis at the Botany Photo of the Day website:
 
“Impatiens capensis is an introduced and invasive species in the  Pacific 
Northwest , west of the Cascades. Peter Zika addressed this issue in a 2006 
paper, "The status of Impatiens capensis (Balsaminaceae) on the
Pacific Northwest coast", published in the Journal of the Torrey Botanical Club, 
vol. 133 pp. 593-600. In fact, I. capensis is spreading into the habitats of the 
uncommon native  I. ecalcarata west of the Cascades, and the two species are 
hybridizing. This has created a situation where the native species is 
potentially being out-competed by both the introduced species and by their 
hybrids. Zika has published another paper on the hybrid, which he has named 
Impatiens x pacifica , see "Impatiens x  pacifica (Balsaminaceae), a New Hybrid 
jewelweed from the Pacific Northwest Coast of North America", Novon vol. 16, pp. 
443-448, 2006.”
 
Add this spp. to I. glandulifera (a big problem) and I.balfourii (an escaping 
species which may be a problem in the future), and we’ve got our hands full out 
here with the touch-me-nots.
 
 
Dominic Maze| Invasive Species Coordinator 
City of PortlandEnvironmental Services
1120 SW 5th Avenue, Room 1000
Portland,  Oregon 97204
p:  (503) 823-4899
f:   (503) 823-5344
dominic.maze at portlandoregon.gov

________________________________
 
From:apwg-bounces at lists.plantconservation.org 
[mailto:apwg-bounces at lists.plantconservation.org] On Behalf Of Katie Fite
Sent: Monday, July 18, 2011 5:46 PM
To: apwg at lists.plantconservation.org
Subject: [APWG] Jewelweed
 

Has anyone had any experience with jewelweed (Impatiens) native to the eastern 
U. S. becoming weedy in valley marsh habitats in the intermountain West? 


I see that jewelweed Impatiens capensis (orange jewelweed) is listed as a King 
County  (WA) “Weed of Concern”. 


This species is shown as having a yellow flowered form, which is what we are 
seeing.

http://www.kingcounty.gov/environment/animalsAndPlants/noxious-weeds/laws/list.aspx


Katie Fite
Western Watersheds Project
katie at westernwatersheds.org
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