Posted by brianc on October 12, 2000 at 09:47:16:
In Reply to: "Toxic"? posted by Gerry Smith on October 12, 2000 at 09:23:13:
I'm not familiar with the designation of this particular species. I'm probably the only person on this board who did graduate work in weed science though, so I'll give you my guess. The term used in weed science for pest species is "noxious." A weed is any plant growing where it is not wanted. Bermuda grass is considered a desirable lawn choice by some people (not me!). When that same grass gets into nearby flower beds it becomes a weed. An exotic species is one of "foriegn" origin - non-native. Not all exotics are considered weeds, many are brought in intentionally others not. A high percentage of the plants commonly seen in California are exotic in origin. Many of the annual grasses that cover our hills came in with the original Spanish explorers as seeds in animal feed. They out competed the native annual bunch grasses.
Now, for the real policy wonks, here's the legal definition of a noxious weed. This comes from the Federal Noxious Weed Act of 1974.
A noxious weed is defined as "any living stage (including, but not limited to, seeds and reproductive parts) of any parasitic or other plant, of a kind or subdivision of a kind, which is of foriegn origin is new or not widely prevalent in the United States, and can directly or indirectly injure crops, other usefull plants, livestock or poultry or other interests of agriculture, including irrigation, or navigation, or the fish, or widlife resources of the United States or the public health."