Malveae

Abstract: Lavatera andMalva are circumscribed by epicalyx characters, but the distinction is untenable on this basis. Morphological characters and phylogenetic trees from rDNA ITS sequence data indicate the presence of two well-supported species groups different from the traditional genera. One group includes a mixture of closely related species in both genera and forms a more broadly circumscribedMalva, including most disjunctLavatera species—notably four of western North American islands, one Australian and one Canarian species. The other group forms a more narrowly definedLavatera. Another CanarianLavatera species may be a common ancestor to the two groups.

Abstract: Phylogenetic relationships among genera of tribe Malveae (Malvaceae, subfamily Malvoideae) were reconstructed using sequences of the internal transcribed spacer (ITS) region of the 18S-26S nuclear ribosomal repeat. Newly generated sequences were combined with those available from previous generic level studies to assess the current circumscription of the tribe, monophyly of some of the larger genera, and character evolution within the tribe. The ITS data do not support monophyly of most generic alliances as presently defined, nor do the data support monophyly of several Malveae genera. Two main well-supported clades were recovered, which correspond primarily to taxa that either possess or lack involucral bracts, respectively. Chromosomal evolution has been dynamic in the tribe with haploid numbers varying from n = 5 to 36. Aneuploid reduction, hybridization, and/or polyploidization have been important evolutionary processes in this group.

Abstract: polyploid origin, has resulted in the realignment of Anoda Cav, Bakeridesia, Callirhoe Nutt, Napaea L, Periptera DC, and Sidalcea A Gray The data also support the thesis that the base chromosome number of the Malveae, or at least of the Abutilon alliance, is x = 8; that the genera of the New Zealand and Australian Plagianthus alliance were probably derived from abutiloid ancestors; that the generic boundaries of Pseudoabutilon R E Fries and Wissadula Medic require redefinition; and that the Chilean Malacothamnus chilensis (Gay) Krapov is generically distinct from the North American species of that genus Callirhoe may be cytologically the most complex genus of Malveae It includes both euploid and aneuploid series, probably supernumerary chromosomes, and perhaps structural rearrangements in the form of reciprocal translocations between non-homologous chromosomes

Abstract: The classification and phylogenetic relationships of the genera within the Malvaceae have received little recent attention despite the widespread distribution of the family and the economic importance of some of its members. Traditional classifications have utilized morphological, biogeographical, and chromosomal data. We have mapped the chloroplast genome from 23 of the approximately 110 genera of Malvaceae, representing four of the five tribes. Six equally most parsimonious phylogenetic reconstructions resulted from parsimony analysis of 236 variable restriction sites. Members of the Hibisceae and Malvavisceae did not form monophyletic groups, while members of the Gossypieae and Malveae did form monophyletic groups. The Abutilon alliance formed a sister group to the remainder of the Malveae. Members of other alliances within the Malveae did not form the monophyletic groups proposed in the classical literature. The Malvaceae are a worldwide family with a primary concentration of genera in the tropical regions. There are approximately 110 genera and over 2,300 species divided into five tribes: Decaschistieae, Gossypieae, Hibisceae, Malvavisceae, and Malveae. Previous workers have made strong statements supporting recognition of the tribal units in the family. Bates and Blanchard (1970, p. 927) stated about the tribes: "In an evolutionary sense these tribes probably have been long distinct and thus should be considered separately when evaluating most kinds of relationships within the family." Fryxell (1975, p. 172) stated: "Although exceptions are known for certain characters given in the table, these exceptions do not detract from the conclusions that the tribes are natural groups." Both were speaking of the then four recognized tribes. Fryxell (1975) went on to describe the fifth tribe: Decaschistieae. The tribes range in size from the Decaschistieae with only one genus, to the Malveae with nearly 70 genera. Many authors have discussed the circumscription of the family (e.g., Edlin 1935; Kearney 1951; Bates 1968; Fryxell 1968a). They have primarily focused on two issues: 1) how the Malvaceae differ from the other families in the Malvales, and 2) how the genera within the family are related. We will concentrate on the second issue in this paper. Tribal circumscription in Malvaceae currently is based on morphological, chromosomal, and biogeographical data. Fryxell (1968a) summarized the nomenclatural history of the Gossypieae and the Hibisceae and argued strongly for retaining the members of these tribes in the Malvaceae. Fryxell (1975) provided supportive evidence for the recognition of the new tribe Decaschistieae. Some of the most detailed work with genera in the Malvaceae has been with the Malveae by Bates (1968) and Bates and Blanchard (1970). These papers used morphological, biogeographical, and chromosomal data to divide the Malveae further into informal groups called "alliances." These are not nomenclaturally recognized categories but serve to associate related taxa. The objectives of this study were to test hypotheses of monophyly of groups in the Malvaceae, with particular emphasis on the intergeneric relationships in the Malveae. Data from chloroplast DNA (cpDNA) restriction site mapping are used to hypothesize phylogenetic relationships. MATERIALS AND METHODS Representatives of four of the five tribes were sampled (Table 1). A single species was sampled