Lone Aagesen

The phylogeny of the alstroemeriaceae, based on morphology, rps16 intron, and rbcL sequence data

Abstract Separate and combined analyses of morphology, rps16, and rbcL data were conducted on a total of 27 Alstroemeriaceae species including 23 Alstroemeria, three Bomarea, and Leontochir. We wished to examine the monophyly of Alstroemeria and Bomarea as well as explore the phylogenetic position of Leontochir and two controversial monotypic genera segregated from Alstroemeria: Schickendantzia and Taltalia. Monophyly of the Chilean and Brazilian Alstroemeria species were explored. The results support monophyly of the family. Alstroemeria and Bomarea are both monophyletic with the former genus being more strongly supported. Bomarea and the monotypic genus Leontochir form a clade distinguished from Alstroemeria by a set of morphological characters. Bomarea could not be defined by morphological characters without including Leontochir. Resolution within Alstroemeria is only weakly supported and formal subdivisions should not be made until the Brazilian members are revised and/or more appropriate phylogenetic markers at the species level have been found. Alstroemeria graminea or A. pygmaea never appear in a position that makes their segregation from Alstroemeria possible (as Taltalia and Schickendantzia, respectively), without making Alstroemeria paraphyletic. The resolution best supported in this study divides Alstroemeria into subclades roughly corresponding to geography: a clade from northern Chile, a clade from central Chile, and a clade containing the Brazilian species. Most of the trans-andean species could not be unambigously placed by this study. Communicating Editor: James F. Smith

Detecting areas of endemism with a taxonomically diverse data set: plants, mammals, reptiles, amphibians, birds, and insects from Argentina

The idea of an area of endemism implies that different groups of plants and animals should have largely coincident distributions. This paper analyses an area of 1152 000 km2, between parallels 21 and 32°S and meridians 70 and 53°W to examine whether a large and taxonomically diverse data set actually displays areas supported by different groups. The data set includes the distribution of 805 species of plants (45 families), mammals (25 families), reptiles (six families), amphibians (five families), birds (18 families), and insects (30 families), and is analysed with the optimality criterion (based on the notion of endemism) implemented in the program NDM/VNDM. Almost 50% of the areas obtained are supported by three or more major groups; areas supported by fewer major groups generally contain species from different genera, families, or orders.

A Phylogeny of Piptochaetium (Poaceae: Pooideae: Stipeae) and Related Genera Based on a Combined Analysis Including Trnl-f, Rpl16, and Morphology

Abstract The tribe Stipeae occurs in temperate and warm temperate grasslands of Eurasia, Australia, and America. Although generic circumscription within the tribe has recently undergone significant changes, the American genus Piptochaetium has been clearly defined by morphological and anatomical characters. It includes 36 species and 2 varieties, most of them widely distributed in temperate grasslands of South America. Phylogenetic analyses were conducted in Piptochaetium and allied genera of the Stipeae, in order to test the monophyly of the genus, re-examine infrageneric taxa, and analyze relationships among species of this genus and allied genera of Stipeae. Two chloroplast molecular markers, trnL-F and rpl16, as well as morphology were used. Topology between morphological and molecular data mainly differs in the relationships of Piptochaetium with Anatherostipa and Piptatherum. Molecular and combined analyses yielded two major clades in the tribe: the x  =  11 Clade with Piptochaetium, Aciachne, Anatherostipa, and Jarava vaginata, and the Aneuploid Clade with Jarava, Nassella, and Piptatherum. Monophyly of Piptochaetium was confirmed by morphological and total evidence (morphology and DNA data) analyses. Monophyly of sect. Podopogon, sect. Piptochaetium and Nassella were only supported by the total evidence analysis. Circumscription of Jarava is also discussed.

Macro-Climatic Distribution Limits Show Both Niche Expansion and Niche Specialization among C4 Panicoids.

Grasses are ancestrally tropical understory species whose current dominance in warm open habitats is linked to the evolution of C4 photosynthesis. C4 grasses maintain high rates of photosynthesis in warm and water stressed environments, and the syndrome is considered to induce niche shifts into these habitats while adaptation to cold ones may be compromised. Global biogeographic analyses of C4 grasses have, however, concentrated on diversity patterns, while paying little attention to distributional limits. Using phylogenetic contrast analyses, we compared macro-climatic distribution limits among ~1300 grasses from the subfamily Panicoideae, which includes 4/5 of the known photosynthetic transitions in grasses. We explored whether evolution of C4 photosynthesis correlates with niche expansions, niche changes, or stasis at subfamily level and within the two tribes Paniceae and Paspaleae. We compared the climatic extremes of growing season temperatures, aridity, and mean temperatures of the coldest months. We found support for all the known biogeographic distribution patterns of C4 species, these patterns were, however, formed both by niche expansion and niche changes. The only ubiquitous response to a change in the photosynthetic pathway within Panicoideae was a niche expansion of the C4 species into regions with higher growing season temperatures, but without a withdrawal from the inherited climate niche. Other patterns varied among the tribes, as macro-climatic niche evolution in the American tribe Paspaleae differed from the pattern supported in the globally distributed tribe Paniceae and at family level.

Evolution of pollination by frugivorous birds in Neotropical Myrtaceae

Bird pollination is relatively common in the tropics, and especially in the Americas. In the predominantly Neotropical tribe Myrteae (Myrtaceae), species of two genera, Acca and Myrrhinium, offer fleshy, sugary petals to the consumption of birds that otherwise eat fruits, thus pollinating the plants in an unusual plant-animal interaction. The phylogenetic position of these genera has been problematic, and therefore, so was the understanding of the evolution of this interaction. Here we include new sequences of Myrrhinium atropurpureum in a comprehensive molecular phylogeny based on a balanced sample of two plastid and two nuclear markers, with the aim of providing the historical framework of pollination by frugivorous birds in Myrteae. We developed 13 flower and inflorescence characters that comprehensively depict the macroscopic morphological components of this interaction. Bayesian and parsimony phylogenies concur in placing both Acca and Myrrhinium in a clade with Psidium species; with Myrrhinium sister to Psidium. Mapping of morphological characters indicated some degree of convergence (e.g., fleshy petals, purplish display) but also considerable divergence in key characters that point to rather opposing pollination strategies and also different degrees of specialization in Acca versus Myrrhinium. Pollination by frugivorous birds represents a special case of mutualism that highlights the evolutionary complexities of plant-animal interactions.