|Doddering Towards Control Of Invasive
July 7, 2006
(For an illustrated version, download the attached PDF file)
For perhaps the first time ever in Richmond, a plant invasion edged out a home invasion for attention from the local press. The West County Times set off a mad scramble to identify and eradicate local infestations of Japanese dodder before it wraps all our prized landscaping up like the invasion of the body snatchers.
County destroying parasitic plant
By John Geluardi
June 29, 2006
An aggressive vine that sucks the life from shrubs, plants and trees has been discovered in four locations around West Contra Costa County. The Japanese dodder is a parasitic plant that could dramatically alter native creek vegetation, disrupt bird habitats and damage agricultural crops, according to the Contra Costa County Department of Agriculture. The dodder vine looks like a thick, bright yellow-orange spaghetti noodle with small scaly, green leaves. The vampire-like plant siphons off energy from trees and plants by sinking its roots into their vascular systems.
The plant is capable of spreading quickly because it is not particular about hosts. It can attach itself to most ivies, nearly all native trees, most fruit trees and a variety of ornamental plants. Once attached, the vine blocks sunlight by thickly shrouding its host.
'It can completely drape over trees, making it impossible for birds to nest,' said Chief Deputy Vince Guise. 'It's very robust, and we're not sure exactly where it's going yet. We're hoping it can be eradicated.'
The Japanese dodder has been discovered in Cerrito Creek on the Albany and El Cerrito border and in Wildcat Creek in San Pablo near the Richmond border. It has also been found on a roadside fence at the Port of Richmond.
The Department of Agriculture is scheduled to eradicate the plant at all three locations today. At Wildcat Creek an 18-foot oak tree will have to be cut down and removed.
State botanist Fred Hrusa suspects the plant is being imported from Asia for medicinal purposes. Some Asian cultures believe dodder stems are a male aphrodisiac.
It is illegal to import dodder seeds unless they have been properly treated. A vial of untreated seeds was recently discovered for sale, however, in a Shasta County health food store. The Japanese dodder was first discovered in Contra Costa County last summer on private property in San Pablo. In 2004 the plant was found in Redding and Los Angeles County. It has also been found in Sacramento and Yuba County.
IF YOU SEE DODDER, Do not remove the weed yourself. Report the plant immediately to the Contra Costa County Department of Agriculture at (925) 646-5250.
Japanese dodder (Cuscuta japonica) is an annual, parasitic vine that has recently been introduced into the United States. Japanese dodder is listed as a Federal Noxious Weed. Many species of dodder, some native and some exotic, occur in the United States. Japanese dodder parasitizes host plants by penetrating the vascular tissue of the host with structures called haustoria. Severe infestations can kill host plants. Japanese dodder is native to Asia and several infestations in Texas, Florida, and South Carolina have recently been found.
Here is where it gets interesting. It turns out that the dodder identified at the Port of Richmond is on a fence at National Gypsum, ironically sucking the life out of another invasive exotic plant, Algerian ivy (Hedera canariensis).
Meanwhile, Richmond photographer Ellen Gailing reports what looks like an infestation on the beach at Point Molate. Not so, says Beyaert. This is Californiaís own native species of dodder.
California dodder (Cuscuta californica) is a leafless, parasitic, viney plant with slender orange to yellowy stems which are each fastened to their host organism by means of a knobby root-like structure called a haustoria, which allows it to draw its nourishment from the host. If any leaves are present, they are minute and scale-like. The flowers are small, white, squat, urn-shaped, and arranged in loose cymose or paniculate clusters. Both calyx and corolla are 5-cleft, the calyx somewhat shorter than the corolla tube with spreading to recurved lobes, and the corolla shallowly campanulate with lanceolate, acute, spreading to reflexed lobes. The fruit is a globose capsule with light brown and rounded seeds somewhat flattened on two sides. There are several species of dodder in Southern California and they tend to be fairly specific to host plants, but I have found this not always to be the case. The one here, species californica, seems to be mostly partial to the buckwheats, sages, deerweed and Haplopappus. It can be differentiated from any other dodder species that might grow in the same area by the length of the corolla appendages, which are small scale-like structures with somewhat irregularly laciniate tips attached to the corolla at the base of the stamens. Californica appendages are either lacking or very short, to 0.1 mm, while other species have appendages that are from 0.7 to 2.5 mm. Subinclusa is the other common dodder and it has slender flowers with long tubes with petal tips that mostly stay straight out and absent or very short stamen filaments. It also tends to be more orangey than yellow. California dodder inhabits many plant communities from sea level to 8200' in most of cismontane California and occasionally on the deserts, and blooms from May to July.
Now why am I intrigued enough to write a lengthy explanation of all this? Itís because it is the first time I have seen anyone take an interest in invasive exotic plants in Richmond.
It turns out that Richmond has probably the most comprehensive and advanced ordinance in California directed at the control of invasive exotic plants. Unfortunately, I know of no instance of it actually being enforced.
Most people around Richmond would probably believe that an interest in invasive exotic plants is an extravagance that a City with our problems can ill afford, but I can assure you that this is a major focus of state and federal government. See www.cdfa.ca.gov/noxtimes, http://www.cnps.org/archives/exotics.htm, http://plants.nrcs.usda.gov/cgi_bin/noxious.cgi, http://ucce.ucdavis.edu/files/filelibrary/5319/4898.pdf, http://rfs.berkeley.edu/pdf/Invasive%20Exotic%20Vegetation%20Mgmt%20Plan.pdf, and so on.
In Richmond, it is illegal for any invasive exotic plant to exist uncontrolled on private property. The following excerpt from Richmondís Weed Abatement Ordinance (RMC 9.50) describes both generally and specifically what constitutes a weed:
(f) "Weed" means any plant, or any part of a plant, including but not limited to seeds, seedlings, roots, branches, trunk, root crown suckers, or rhizomas suckers, that is out of place and is therefore a pest causing a fire hazard, traffic hazard, visual blight, ecological detriment or other risk to the public interest. A weed can be annual, biennial or perennial in reproductive habit and take the form of, but not be limited to, a tree, bush, ground cover, forb, grass, vine, bulb or aquatic species. All weeds that are listed as noxious or quarantined by the Federal and State governments or which are invasive exotic species are included. Periodically, the Contra Costa Agricultural Commissioner or the City of Richmond Pest Control Advisor, licenses in category "E", can deem a plant species a weed to address a localized pest problem.
(g) "Invasive Exotic Species" means invasive and aggressive non-native plants which tend to spread into the surrounding ecosystems and displace native plants because they are more aggressive in their growth habits, or because they put out more seed that lasts longer in the soil, or because there is nothing to eat them, compete with them, or disease them in the California ecosystem.
Invasive exotic species that may be found in Richmond include, but are not limited to, the following:
(Amended by Ordinance No. 32-97 N.S.)
Richmondís invasive exotics can most readily be found in large tracts of unmanaged and undeveloped land, such as the Chevron property, the Canal Boulevard quarry, the Union Pacific parcel west of I-580 and the Richmond Annex. Unfortunately, they are also common in East Bay Regional Parks, such as the Miller-Knox Regional Shoreline. You can find a stand of Pampas grass just south of City Hall on the plot where Toll Brothers Marina Bay Westshore project is slated to be constructed.
These large stands are a problem for everyone because they constitute a hugh and growing seed bank that continues to spread these plants throughout the City. Not only do they displace native ecosystems, these invasive exotics are also among the most flammable of plants and constitute a far higher fire hazard than the natives they displace.
What can you do about it? By clicking on ďreply to all,Ē you can email the Richmond city manager, the City Council and the fire chief demanding that Richmondís Weed Abatement ordinance be enforced and that large property owners be required to eliminate illegal invasive exotics on their property.