| الوصف: |
Four new combinations in Malva, M. assurgentiflora, M. lindsayi, M. occidentalis, and M. wigandii, and five replacement names, M. australiana, M. canariensis, M. dendromorpha, M. linnaei, and M. pacifica, are proposed to accommodate species of Lavatera that are more closely related to the type species of Malva than they are to the type species of Lavatera. These species are in the "Malvoid group," discussed by Ray in an earlier paper. One other Lavatera species that should also be placed in Malva is discussed but not formally transferred. Some lectotypes and neotypes are designated. Elsewhere (Ray, 1995), I analyzed and discussed the relationships among species of Malva L., Lavatera L., and six outgroups. I described an analysis of morphological character data that initially appeared to have little value. That analysis was followed by an extensive molecular study and a reinterpretation of morphological characters that brought to light a new way to view these genera and problems associated with them. Ray (1994) and Ray (1995) included extensive discussions of morphological characters and evolutionary trends, generic relationships, relevant literature, chromosome numbers, biogeography, and dispersal issues and should be consulted for a better understanding of the results and conclusions briefly described here. Based on my analyses of nuclear rDNA "Internal Transcribed Spacer" (ITS) sequence data and morphological characters (Ray, 1994, 1995), I concluded that the species now in Malva and Lavatera are all closely related in comparison to outgroups in Alcea, Althaea, Anisodontea, Callirhoe, and Hibiscus. Among Malva and Lavatera species, at least one well-supported group, consisting of a mixture of species from the two genera, could be defined on the basis of fruit differences and the ITS-based phylogenetic tree. A phylogenetic tree from Ray (1995) showing the results of analysis of ITS is shown in Figure 1. This figure also shows the major species group that can be defined with the additional support of fruit characters, and includes a listing of species that can be assigned to the group on this basis alone. Another more tentative grouping is also shown. Interesting geographic disjunctions in the distribution of species in Malva and Lavatera are indicated. Malva L. and Lavatera L. have been increasingly problematic since Linnaeus (1753) reinterpreted Tournefort's (1706) generic concept for Lavatera and expanded Lavatera to cover a much wider range of species than Tournefort intended. Tournefort originally described the genus to segregate Lavatera trimestris (a species with relatively unusual characteristics) from Malva on the basis of fruitaxis characters. Linnaeus disregarded this and used epicalyx characters to distinguish the two genera. Lavatera trimestris L. has an unusual epicalyx that may have led Linnaeus to use this character, but the epicalyx of L. trimestris is atypical in comparison to those of nearly all other species traditionally included in Lavatera and Malva. These genera have long been separated by most workers on the "unsatisfactory" (Fernandes, 1968a) basis of fusion or non-fusion of epicalyx bracts. I found the use of epicalyx characters for the generic distinction to be untenable based on extensive morphological and molecular analyses (Ray, 1994, 1995). Several species presently in Lavatera are closely related to species in Malva, in particular to the type species Malva sylvestris L. In fact, some species currently included in Lavatera are more closely related to Malva sylvestris than are some other species traditionally included in Malva; they are among the core Malva species. My "Malvoid group" (see Fig. 1) includes some Malva species plus those species currently included in Lavatera that are very closely related to Malva sylvestris L. These close relationships among Lavatera and Malva species are strongly supported by the analyses of ITS data and by fruit characters (Ray, 1995). When the analysis is forced to retain the traditional division between the genera, the trees become significantly longer. Maximum likelihood testing using the forced tree also shows that, given the ITS data, the traditional generic arrangement (based on the epicalyx) is significantly less likely than the tree found. Species in the Malvoid group (so named because it includes the type species of Malva) have true mericarps that: (a) are rounded in only the axial direction on the abaxial side, (b) have lateral angles NovoN 8: 288-295. 1998. This content downloaded from 207.46.13.180 on Thu, 08 Sep 2016 04:49:22 UTC All use subject to http://about.jstor.org/termsTest Volume 8, Number 3 Ray 289 1998 New Combinations in Malva |
