BALEE & MOORE: SIMILARITY AND VARIATION IN PLANT NAMES 231

(Sandw.) Willd., Inga auristellae Harms, and Inga thibaudiana DC. (Ducke
1949:29), Astrocaryum vulgare Mart. 'tucumd' (Bal6e 1988:47; Wessels Boer
1965:132), Orbignya phalerata babassuu' (Anderson 1983), Theobroma
speciosum Willd. ex Spreng. 'cacauf (Ducke 1953: 14), Dialium guianense
Benth. 'jutaipororoca' (Ducke 1949: 112), Solanum spp. (Lisboa ct al. 1987:55),
and Trema micrantha (L.) Blume 'trema' (Lisboa et al. 1987:55). Neotropical
plant domesticates (Table 3) are completely dependent on human
management for their long-term propagation; most, if not wholly incapable of
setting seed, are producers of minuscule quantities of viable seed. These
species are often parthenocarpic as a result of human interference--that is,
their genotypes have been altered through domestication.
 To measure the degree of similarity between two languages, we look at
 pairs of words such that the word in A and the word in B refer to the same
 species. The number of such pairs which are "similar" and the number which
 are "different" are then tabulated, the ratio between them being the degree of
 similarity.
 In order to define "similarity" adequately, it is necessary to distinguish
 "literal" plant words from "metaphorical/descriptive" (henceforth called simply
 metaphorical) plant words, a distinction which proves to be of crucial analytical
 importance. In our usage, "literal" plant words are those which contain a literal
 plant morpheme; they may contain other morphemes as well. Literal plant
 morphemes are here defined as those which have as their sole referent a
 specific plant, excluding thereby general life form morphemes such as 'tree' or
 'herb.' The word 'oak' in English, for example, refers only to this kind of tree
 and to nothing else--the association between the word and its referent is purely
 arbitrary. The terms 'live oak', 'post oak', and 'oak tree' are also literal since
 they contain the literal morpheme 'oak'. Likewise, in the Tupi-Guarani
 languages under study, the words for Inga nobilis Willd. (Table 2) are literal in
 the three languages for which terms were collected: Ar ifia-pa ka-'i 'Inga-long-
 tree', As yurupi-rana-iga 'throat-similar-Inga' and K 4ga-howi-'i 'Inga-blue-
 tree', since they all incorporate the literal morpheme ifia/iga 'ingA'.
 Two literal plant words are considered to be similar if their literal plant
 morphemes are similar, regardless of the other morphemes occurring in the
 word. Thus, the three words for 'ingA' above constitute three pairs (Ar-As, Ar-
 K, As-K) of similar words.
 In our usage, "metaphorical" names are those which do not contain a
 literal plant morpheme, or if they do contain a literal plant morpheme, it is
 being used metaphorically (i.e., the class of plants designated by the whole
 metaphorical term is not a subset of the class designated by the literal
 morpheme.) In English, 'dogwood' is an example of a metaphorical plant term,
 since neither 'dog' nor 'wood' refer to a specific plant, as does 'oak.' The term
 'poison oak' is also metaphorical, since it is not botanically a kind of oak at all.
 Similarly, in the Tupi-Guarani data, the Ka'apor word for Tapirira guianensis