Unisexual organisms present special, often complex, taxonomic problems, including the basic question of whether to provide formal names for certain clones. In the past, all-female forms that were morphologically distinct from their closest relatives were named and treated as any other morphological species. With the growing awareness, however, that certain clones are of hybrid origin and that some depend on sperm from sympatric bisexual (gonochoristic) congeners in order to reproduce, questions of which organisms should be named (and which ones should not) became more difficult to resolve (Maslin, 1968; Schultz, 1969). Recently, Dubois and Gunther (1982) argued strongly that all-female forms of hybrid origin that depend on sperm for reproduction by means of gynogenesis or hybridogenesis should not be regarded formally as species. They proposed the terms klepton and synklepton for such organisms and their bisexual ancestors. Their arguments applied to the unisexual fishes and amphibians among the vertebrates, but not to the parthenogenetic reptiles. In the present paper, I focus on the allfemale forms that reproduce independently and in the absence of sperm, by parthenogenesis. Among the vertebrates, this includes a number of reptiles (reviewed by Cole, 1975) of which the most thoroughly studied lizards had a polyphyletic origin involving interspecific hybridization of bisexual ancestors (Lowe and Wright, 1966; Neaves, 1969; Uzzell and Darevsky, 1975; Parker and Selander, 1976; Moritz, 1983; Good and Wright, 1984). In addition, genetic analyses of laboratoryreared individuals demonstrate that lineages of parthenogenetic lizards are indeed clones (Cole, 1979; Dessauer and Cole, 1980, unpubl. manuscript; Hardy and Cole, 1981). Similar phenomena have been found among some of the parthenogenetic invertebrates and their relatives (e.g., Suomalainen et al., 1976; White et al., 1977), and these phenomena may be more widespread than is generally recognized. Since these animals are quite unconventional in many aspects of systematics and there are different views on which of them, if any, should be named (Maslin, 1968; Morafka, 1977; B6hme, 1982), I review basic issues here with hopes of contributing to a consensus for uniform taxonomic treatment of such organisms. Also, I propose specific guidelines for the taxonomic treatment of parthenogenetic species, accommodating hybrid origins when pertinent, as discussed next for certain North American whiptail lizards (genus Cnemidophorus; Teiidae).