Water Primrose, Floating (Ludwigia peploides) on Jan 19, 2016
Submitter does not have a specimen
EDRR Status: Population treated
Description of specimen
They have yellow flowers and it has some 4 feet tall stems in the summer, and it forms dense mats in the marshy areas of this pond.
Reporter
Jan. 19, 2016, 1:55 a.m.
Thank you so much for your report! I will be forwarding this report to an expert in Keizer, and either he or I will inspect the site to verify the plant species. You mentioned you thought it may be yellow flag iris. Another possibility is water primrose, a robust yellow-flowered floating plant that creates dense mats, as you described. Here is some information on those plants: http://www.kingcounty.gov/environment/animalsAndPlants/noxious-weeds/weed-identification/floating-primrose-willow.aspx I hope you find that useful.
I will do my best to get back to you once the site has been verified. Thank you again for your interest in invasive species!
Tanya Beard
Marion County Public Works
tbeard@co.marion.or.us
Tanya Beard
Jan. 19, 2016, 5:26 a.m.
I am pasting into this response an excerpt from an email I received from the person managing the site in question. I hope you find it informative and comforting:
Yes, there is both Ludwigia[floating primrose] and Yellow Flag[iris] in the pond closest to the River at KR[Keizer Rapids] park. We actually treated both of them in September. That title on the slide should say two weeks after treatment, but if you look close you can see the large clumps of Iris on the margins of the pond. The project was a bit of an EDDR action for the Parks guys (They didn't know they had any weed problems until I started working here in September ;-). So I had them jump on it and we will see what happens. Those Iris were literally under 17' of water about 3 weeks ago. We will continue to manage the problem and gather data on what is working.
Tanya Beard
Jan. 19, 2016, 10:58 p.m.