The World Wide Web and other computer-based media are new teaching resources for plant identification. The purpose of the experiments reported here was to test whether learning plant identification for woody and herbaceous plant material over the web was as effective, more effective, or preferred by undergraduate students when compared with instruction in the greenhouse. Students were exposed to web and greenhouse instruction (Exp. 1, N = 47; Exp. 2, N = 225) or they were randomly assigned to web or greenhouse learning conditions (Exp. 2, N = 225; Exp. 3, N = 224). The dependent measure was accuracy on identification tests of live specimens in the greenhouse. In each case, mean scores of participants receiving live instruction were significantly higher than those receiving web instruction. Questionnaire data revealed that students preferred live instruction over web instruction, that students perceived live instruction as superior to web instruction, that they preferred to learn new plant material in the classroom rather than on the web, and that web learning was frustrating. The findings indicate that web instruction is not in general superior to live instruction for plant identification, when students are required to use web instruction. (Contains 2 tables.)