People have talked about some of the reasons why fieldwork is important in taxonomy, but we haven't mentioned the most fundamental reason. We need to know exactly how species overlap in space, and what they do when they overlap. Do they form rare hybrids? Do they form so many intergrades that most individuals cannot be unambiguously identified? And how much variation is there in each species in the regions where they don't overlap? The behavior of populations is critically important when trying to identify biological (as opposed to morphological) species. And herbarium records are often not detailed enough to determine whether two species really overlap in their actual habitat. Herbarium specimens are still very important, though. We need some convenient way of comparing plants side by side when the need arises, and herbarium specimens (especially those coupled with flowers preserved in alcohol rather than pressed) afford that opportunity. Lou