The assertion that there is a social component to children's construction of knowledge about natural phenomena is supported by evidence from an examination of children's classification schemes for plants. An ethnographic study was conducted with nine sixth grade children in central Texas. The children classified plants in the outdoors, in a sorting task, in a slide identification task, and in a free listing task. Of the nine major plant categories used by the children, the labels for eight would be recognized by adults: plants, tree, bush, flowers, cactus, weeds, grass, vines. The children's classification scheme differed from that of botanists but strongly resembled that of adult laymen, demonstrating a socially constructed system of classification. Kempton (1981) calls this a folk classification scheme. Reliance on a prototype allows communication to occur between individuals despite idiosyncratic differences in meaning. Contains 16 references. (Author)