In your 8/3/98 issue, Robert Nold takes me to task over my 6/22/98 essay, "It Rhymes With Scourge."
Robert admits that donkeytail spurge has "escaped from Boulder-area gardens and established itself in some areas," but is not a "fast-moving, aggressive invader." Boulder Mountain Parks would disagree; it lists donkeytail spurge as an invasive exotic and has identified 15 serious outbreaks of it in Boulder Mountain Park alone. How one chooses to characterize this status is a matter of opinion.
Robert is correct about the native status of the wild rose; there are several native species generally represented by Rosa nutkana. The one I referred to, introduced by European gardeners, is Rosa eglanteria, the "Eglantine" of Shakespeare and now common on the West Slope of the Cascades and the Sierra Nevada. I should have asserted that "Even some species of wild rose were introduced by European gardeners' rather than simply state that wild rose was introduced to North America. As far as thistles go, there are both native and non-native species all over the continent, the most famous of which (Russian thistle) is certainly an exotic.
Much to my chagrin, Robert is entirely correct about the European origin of dandelion, chicory and salsify. The ubiquitous presence of these species in North America should, however, be a lesson in the dangers of introducing exotic plants, not a reason to minimize those issues. I should have accorded them an historic claim, not an "ancient" one.
I appreciate Robert's remarks but find it difficult to agree with his conclusions; once again, matters of degree often translate into matters of opinion.