Poa L., is known as a highly diverse cosmopolitan genus with taxonomic difficulties that includes unknown species and species with uncertain affinities mainly in West Asia and North Africa. Poa also exhibits a close relationship with two West Asian genera, Eremopoa Roshev. and Oreopoa H. Scholz & Parolly. This study was conducted to: 1) fill the gap of information on the affinities between Poa species with an emphasis on West Asian Poa; 2) revise and evaluate the accuracy of traditional infrageneric classification of West Asian Poa; and 3) clarify the relationship between Poa and two allied genera of Poaceae Barnhart, Eremopoa and Oreopoa. DNA molecular evidence from present phylogenetic analyses of West Asian species of Poa, Eremopoa and Oreopoa, resulted in some great findings as follow: I) Poa caucasica Trin., which is currently assigned to subsection Nivicolae of section Poa from subgenus Poa resolved as a unique new distinct lineage within Poa. II), New treatments are suggested for Poa densa Troitsky, Poa masenderana Freyn & Sint., Poa cenisia All., Poa psychrophila Boiss. & Heldr. and Poa lipskyi. III) Three unclassified species of Poa pseudobulbosa, Poa diversifolia and Poa aitchisonii are assigned here to subgenus Poa and supersection Poa. IV), The present molecular evidence supports inclusion of Eremopoa in Poa and confirms reduction of Eremopoa to a level of subgenus of Poa. V) Present phylogenetic analyses also indicate that monotypic genus Oreopoa H. Scholz & Parolly is part of Poa. These findings require an urgent modification in subgeneric and sectional classification of the genus Poa.

The genetic structure of 26 natural populations of three species (S. tridecemlineatus, S. mexicanus, and S. spilosoma) of the Ictidomys subgenus of ground squirrels was analyzed using chromosomal and electrophoretic techniques. Chromosomal variation was not observed in S. mexicanus, and only slight karyotypic variation was found in the other two species. Chromosomal evidence indicated hybridization between S. tridecemlineatus and S. mexicanus, placing these species within the classical definition of semispecies. Analysis of electrophoretic variation at 29 genetic loci indicated close genetic relationships between these species. Evolution in Ictidomys appears to be linked with Pleistocene events, and speciation appears to have occurred within the last 155,000 years.

Psathyromyia shannoni por um longo tempo foi considerada a espécie de flebotomíneo com a mais ampla distribuição nas Américas, desde os Estados Unidos até a Argentina. Contribuíram para isto a inclusão em sua sinonímia de quatro espécies: Phlebotomus limai, Ph. bigeniculatus, Ph. microcephalus e Ph. pifanoi. Em uma primeira fase deste estudo um grupo de espécies muito próximas à Pa. shannoni foi identificado e denominado de Complexo Shannoni e foi visto que Pa. limai e Pa. bigeniculata eram espécies válidas, Ph. pestanai era sinônimo-júnior de Pa. limai e havia ainda a necessidade de descrever Pa. ribeirensis. No entanto, questões sobre a validade dos demais sinônimos foram levantadas e ao conduzir o estudo, surgiram outras questões, como a delimitação do subgênero, composição da série Lanei e série Shannoni e a afinidade entre as suas espécies, que precisavam ser esclarecidas. Objetivos. Revisar a taxonomia das espécies do subgênero Psathyromyia e realizar uma análise filogenética. Material e métodos. Exemplares de todas as espécies do subgênero Psathyromyia depositados em coleções entomológicas foram examinados para obtenção de dados morfológicos e morfométricos para uma revisão taxonômica e análise filogenética. Dados foram levantados da literatura e dos espécimes depositados nas coleções para a construção de mapas sobre a distribuição geográfica das espécies objeto de estudo. Resultados e Conclusões. Com a revisão taxonômica Pa. baratai foi descrita e sua distribuição geográfica foi apresentada. Phlebotomus microcephalus foi excluída da sinonímia de Pa. shannoni e inserida como sinônimo-júnior de Pa. bigeniculata. Psathyromyia pifanoi também foi retirada da sinonímia de Pa. shannoni, teve sua fêmea descrita e Lu. cuzquena foi incluída como seu sinônimo-júnior. A distribuição geográfica de Pa. shannoni foi redefinida com a retirada das quatro espécies de sua sinonímia, o Complexo Shannoni foi ampliado para 11 espécies, Pa. pifanoi foi retirada deste e considerada isolada no gênero Psathyromyia. A série Lanei (3 spp.) e a série Shannoni foram mantidas em Psathyromyia s. str., no entanto, a série Shannoni passou a ser constituída somente das espécies do complexo (11 spp.), e as demais foram inseridas em outras duas séries propostas: Campbelli (2 spp.) e Volcanensis (4 spp.). Lutzomyia cultellata, Lu. tanyopsis, Lu. ignacioi e Lu. ponsi foram excluídas do gênero e subgênero Psathyromyia e transferidas para o gênero Lutzomyia permanecendo isoladas. Por fim, a análise filogenética demonstrou nas quatro árvores obtidas e uma de consenso estrito que as espécies das séries: Lanei, Campbelli e Shannoni são monofiléticas e a série Volcanensis parafilética. A série Lanei e Campbelli ficaram externas ao clado Psathyromyia s. str. Psathyromyia maya foi posicionada como a espécie mais basal do clado que se refere à subtribo Psychodopygina. Lutzomyia ignacioi, Lu. ponsi e Lu. tanyopsis foram posicionados na subtribo Lutzomyiina e gênero Lutzomyia, bem como Lu. cultellata, agrupada no subgênero Tricholateralis / Psathyromyia shannoni was for a long time considered the sand fly species of the widest distribution in the Americas, from the United States to Argentina. Contributing to this was the inclusion as synonyms of four species: Phlebotomus limai, Ph. bigeniculatus, Ph. microcephalus and Ph. pifanoi. In the preliminary phase of these studies, a group of species very close to Pa. shannoni was identified and denominated the Shannoni Complex and it was seen that Pa. limai and Pa. bigeniculata were valid species, Ph. pestanai was a junior synonym of Pa. limai and there was still a need to describe Pa. ribeirensis. However, questions about the validity of these synonyms have been raised and studies have been undertaken to investigate this issue. As we conducted the study, other questions such as the delimitation of the subgenus, composition of Lanei and Shannoni series\' and the affinity between its species arose that called for clarification. Objectives. To review the subgenus Psathyromyia and perform a phylogenetic analysis. Material and methods. Specimens of all species of the subgenus of Psathyromyia deposited in entomological collections were examined to obtain morphological and morphometric data for taxonomic revision and phylogenetic analysis. Data were collected from the literature and from the specimens deposited in the collections to make maps of the geographical distribution of the species object of study. Results and Conclusions. With the taxonomic revision, Pa. baratai was described and its geographical distribution was presented. Phlebotomus microcephalus was excluded from synonymy with Pa. shannoni and inserted as junior synonym of Pa. bigeniculata. Psathyromyia pifanoi was revalidated, its female was described and Lu. cuzquena was included as its junior synonym. The geographical distribution of Pa. shannoni was redefined with the withdrawal of the four species from their previous synonymy, the Shannoni Complex was expanded to include 11 species, Pa. pifanoi was removed from the Complex and considered isolated in the genus Psathyromyia. The Lanei (3 spp.) and Shannoni series were maintained in the subgenus Psathyromyia, however, the Shannoni series was reduced to the species of the Shannoni Complex (11 spp.), and the other species that had belonged to this series were inserted in two other proposed series: Campbelli (2 spp.) and Volcanensis (4 spp.). Lutzomyia cultellata, Lu. tanyopsis, Lu. ignacioi and Lu. ponsi were excluded from the genus Psathyromyia and transferred as isolated to the Lutzomyia genus. Finally, the phylogenetic analysis resulted in four trees and one of strict consensus in which the species of the Lanei, Campbelli and Shannoni series are monophyletic and the Volcanensis series is paraphyletic. The Lanei and Campbelli series remained outside the Psathyromyia s. str. clade. Psathyromyia maya was positioned as the basal species of the clade that related to the subtribe Psychodopygina. Lutzomyia ignacioi, Lu. ponsi and Lu. tanyopsis were placed in the Lutzomyiina subtribe and Lutzomyia genus, as well as Lu. cultellata, grouped in the subgenus Tricholateralis

Plant fossils from the Citronelle Formation provide a rare window into the Pliocene flora and climate of the northeastern Gulf of Mexico Coastal Plain. Many of the taxa recovered to date inhabit the region today. However, analysis of Pinus pollen grains and fascicles indicates that the dominant pines were members of Pinus subgenus Strobus (i.e., "white pines"). The fascicles have a small, bulbous base lacking a sheath, and bear four or five long, slender needles. These features are typical of white pines. Although macrofossils are rare, 77 to 100% of the dispersed Pinus pollen grains from five localities have sacci continuous with the corpus and verrucae on the cappula, which are characteristics of white pines. This is remarkable, as the northeastern Gulf of Mexico Coastal Plain today is devoid of white pines, and is instead considered a center of diversity for Pinus subgenus Pinus section Pinus subsection Australes. Today, Pinus strobus is the only white pine in the eastern North America and its southernmost distribution only extends into the mountains of Georgia, about 600 km north of the fossil sites. The historical biogeographic relationships of P. strobus to other North American forms are unclear. For example, its close relative, Pinus chiapensis, is present in northeastern Mexico and Central America. The current disjunction between P. strobus and P. chiapensis is 2400 km and includes an arid barrier to dispersal. P. chiapensis is also associated with several other species showing a similar biogeographic pattern. The fossils described here indicate that white pines were more widespread in North America in the recent geological past than previously thought, and imply possible connections between disjunct species that would not be suspected if only current species' ranges and ecological tolerances were considered.