[fosc] new invasive plant, looks like yellow silly-string

Karen Paulsell kpaulsell at pacbell.net
Fri Jun 23 14:21:42 PDT 2006

Susan Scwartz of Friends of Five Creeks found the latest occurrence, and 
has been forwarding info to all local creek-folks. I've uploaded her photo; 
see: http://tinyurl.com/jwthx

A new pest parasite, Cuscuta japonica or Japanese dodder, has been found 
invading the East Bay.
Please be on the lookout and inform your county agriculture office if you 
see it.

The leafless, bright-yellow parasitic vine forms dense tangles on on 
willows, blue elderberry, and wild plums on Cerrito Creek, on the 
Albany-Contra Costa border. Friends of Five Creeks, a volunteer 
creek-restoration group, reported the infestation after seeing an 
Alameda/Contra Costa Weed Management Area alert. There are many native and 
non-native California dodders, but no other forms thick, twisted, bright 
yellow mats in broadleaf trees and shrubs. This dodder is capable of 
parasitizing many hosts:

The two previous California reports were on orchard trees in the Central 
Valley and pittosporum at an apartment building in San Pablo. There is a 
Department of Agriculture quarantine against importing plants or viable 
seed. But the rules are weak. Vince Guise of the Alameda/Contra Costa Weed 
Management Authority reports that seed from a recent, supposedly sterile 
shipment, imported as herbal medicine, were found to sprout readily.

Plants spread both by seed and vegetatively. Once the sticky seed, or the 
long, twisting growing tip, finds a home, it sends root-like hausatoria 
into the host's limbs, sucking out water and nutrients.

Plants should be handled and disposed of with extreme caution. The Weed 
Management Area recommends that you contact them for removal rather than 
doing it yourself. If you do work on the parasite, their recommendation is 
removal of the entire tree or shrub down to the ground, careful double 
bagging of all debris, and disposal where nothing could possibly take root 
(buried in landfill with good soil cover, not composted).

In Alameda or Contra Costa Counties, contact Vince Guise, vguis at ag.cccounty.us.

(Please also let me know if you find it in the Sausal Creek watershed!)

More information about the Fosc mailing list