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Davis, Charles

Lophopterys Adr. Juss. is a South American genus of Malpighiaceae comprising seven species, two of which are described here as new (L. floribunda W. R. Anderson & C. C. Davis and L. occidentalis W. R. Anderson & C. C. davis). The taxonomic history, morphology, circumscription, and systematic position of the genus are discussed, with the conclusion that while the genus is coherent and easily recognized, its relationships in the family are still somewhat obscure. The taxonomy is revised with descriptions, keys, and notes on phenology, habitat, and distribution, and all specimens studied are cited. Illustrations include a distribution map, SEMs of pollen from two species, and drawings of six species.

Premise of the study: The Malpighiaceae include ∼1300 tropical flowering plant species in which generic definitions and intergeneric relationships have long been problematic. The goals of our study were to resolve relationships among the 11 generic segregates from the New World genus Mascagnia, test the monophyly of the largest remaining Malpighiaceae genera, and clarify the placement of Old World Malpighiaceae.

Methods: We combined DNA sequence data for four genes (plastid ndhF, matK, and rbcL and nuclear PHYC) from 338 ingroup accessions that represented all 77 currently recognized genera with morphological data from 144 ingroup species to produce a complete generic phylogeny of the family.

Key results and conclusions: The genera are distributed among 14 mostly well-supported clades. The interrelationships of these major subclades have strong support, except for the clade comprising the wing-fruited genera (i.e., the malpighioid+Amorimia, Ectopopterys, hiraeoid, stigmaphylloid, and tetrapteroid clades). These results resolve numerous systematic problems, while others have emerged and constitute opportunities for future study. Malpighiaceae migrated from the New to Old World nine times, with two of those migrants being very recent arrivals from the New World. The seven other Old World clades dispersed much earlier, likely during the Tertiary. Comparison of floral morphology in Old World Malpighiaceae with their closest New World relatives suggests that morphological stasis in the New World likely results from selection by neotropical oil-bee pollinators and that the morphological diversity found in Old World flowers has evolved following their release from selection by those bees.

The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps from root-parasitic Loranthaceae. These transgenes are restricted to B. virginianum and occur across the range of the species. Molecular and life-history traits indicate that the transfer preceded the global expansion of B. virginianum, and that the latter may have happened very rapidly. This is the first report of HGT from an angiosperm to a fern, through either direct parasitism or the mediation of interconnecting fungal symbionts.

Mascagnia leticiana W. R. Anderson is transferred to Malpighia to become Malphighia leticiana (W. R. Anderson) W. R. Anderson & C. Cav. Davis, on the basis of a new phylogenetic analysis of DNA sequences and morphological characters. The morphology of M. leticiana is illustrated and discussed in the context of the problem of distinguishing between Malpighia and Mascagnia.

Phylogenetic analyses of molecular and morphological data have shown the genus Banisteriopsis to be polyphyletic and the genus Diplopterys to be nested within Banisteriopsis subg. Pleiopterys, which is not in the clade that contains the type of the name Banisteriopsis. Therefore, it is necessary to take up the name Diplopterys for the small genus formerly called that plus subg. Pleiopterys of Banisteriopsis. Adescription of the amplified genus Diplopterys is provided, two new species are described (D. bahianaand and D. carvalhoi), and the following new combinations in Diplopterysare proposed, with all combinations by W. R. Anderson and C. Cav. Davis: D. amplectens, D. cachimbensis, D. caduciflora, D. cristata,D. erianthera, D. heterostyla, D. hypericifolia, D. krukoffii, D. leiocarpa, D. longialata, D. lucida, D. lutea, D. nigrescens, D. nutans, D. patula, D. peruviana, D. platyptera, D. populifolia, D. pubipetala, D. rondoniensis, D. schunkei, D. sepium, D. valvata, D. virgultosa, and D. woytkowskii. Illustrations are provided for D. bahiana, D. cabrerana, D. carvalhoi, D. pauciflora, D. pubipetala, and D. valvata.

The Malpighiaceae are a family of similar to ~1250 species of predominantly New World tropical flowering plants. Infrafamilial classification has long been based on fruit characters. Phylogenetic analyses of chloroplast DNA nucleotide sequences were analyzed to help resolve the phylogeny of Malpighiaceae. A total of 79 species. representing 58 of the 65 currently recognized genera. were studied. The 3' region of the gene ndhF was sequenced for 77 species and the noncoding intergenic spacer region trnL-F was sequenced for 65 species' both sequences were obtained for the outgroup, Humiria (Humiriaceae), Phylogenetic relationships inferred from these data,ets are largely congruent with one another and with results from combined analyses. The family is divided into two major clades, recognized here as the subfamilies Byrsonimoideae (New World only) and Malpighioideae (New World and Old World). Niedenzu's tribes are all polyphyletic, suggesting extensive convergence on similar fruit types; only de Jussieu's tribe Gaudichaudieae and Anderson's tribes Acmanthereae and Galphimieae are monophyletic. Fleshy fruits evolved three times in the family and bristly fruits at least three times. Among the wing-fruited vines, which constitute more than half the diversity in the family, genera with dorsal-winged samaras are fairly well resolved, while the resolution of taxa with lateral-winged samaras is poor. The trees suggest a shift from radially symmetrical pollen arrangement to globally symmetrical pollen at the base of one of the clades within the Malpighioideae. The Old World taxa fall into at least six and as many as nine clades.