Pollination Ecology in the Southwest

Comparisons of the pollination biology of members of a number of genera (Prosopis, Helianthus, Opuntia, and Krameria) widespread in the arid American Southwest are made between sites in the Sonoran Desert of southern Arizona and the dry oak-juniper grasslands of central Texas. As in the majority of cases studied to date in the dry regions of the Southwest, solitary bees are the dominant pollinators in all of the systems examined. Rich arrays of oligolectic bees are associated with Prosopis, Helianthus, and Opuntia, but none with Krameria which offers oils rather than pollen and nectar as the primary floral reward. Nevertheless, Krameria appears to have the most restricted pollination system as none of the other taxa are obligately dependent on their specialist bees. Reward production and bee foraging activity were examined in Opuntia and Helianthus. In Helianthus, bimodal pollen presentation, but near constant nectar production, results in different activity patterns of the specialist and generalist bees visiting the flowers. Reward production is unimodal in the Opuntia species studied, but diurnal phenological differences can result in apparent partitioning of floral resources by foraging bees

A phylogenetic assessment of breeding systems and floral morphology of North American Ipomoea (Convolvulaceae)

A phylogenetic investigation of 68 species and two varieties of tropical and temperate North American Ipomoea (Convolvulaceae) using sequence data from the internal transcribed spacer region (ITS) with parsimony and Bayesian analyses revealed multiple origins of autogamy. By assessing breeding systems and floral morphological characters in the context of this phylogeny, we estimate 16 independent origins of autogamy and 4 subsequent reversions to xenogamy. Transitions to autogamy are associated with reduced pollen-ovule ratios, decreased anther-stigma distance, and small flower size. Although the relationship between floral traits and breeding systems has been described in previous studies, this is the first investigation to examine this association in Ipomoea. - Una investigación filogenética sobre 68 especies y dos variedades de Ipomoea (Convolvulaceae) en las zonas tropicales y templadas de Norteamérica, empleando datos de secuencias de ADN (ITS) con análisis de parsimonia y Bayesianos, demuestran orígenes múltiples de la autogamia. Basándose en la evaluación de los sistemas reproductivos y las características florales en el contexto de los resultados filogenéticos, estimamos 16 derivaciones independientes de la autogamia y cuatro reversiones a la xenogamia. Las transiciones a la autogamia se asocian con relaciones bajas de polen/óvulo, la disminución de la distancia entre las anteras y el estigma, y corolas pequeñas. Aunque estudios previos han tratado de las relaciones entre los sistemas reproductivos y los rasgos florales en las angiospermas, el presente estudio representa el primero que investigua estas relaciones en Ipomoea

(Vol. 02, 1999-12) A Revision of Hoffmannseggia (Fabaceae) in North America

Hoffmannseggia, a genus of the Caesalpinieae, Caesalpinioideae, has been treated as a synonym of Caesalpinia or as a distinct genus with as many as 25 species. Recent molecular and morphological work has provided strong support for a monophyletic Hoffmannseggia distinct from either Caesalpinia or Pomaria. This revision provides the first complete nomenclature and discussion of the 11 species ( 12 taxa) of Hoffmannseggia occurring in North America. Included are a key to the species, maps showing distributions, and photographs of flowers or fruits of six species.Billie L. Turner Plant Resources Cente

(Vol. 01, 1998-05) A Revision of Pomaria (Fabaceae) in North America

The genus Pomaria, described by Cavanilles in 1799 but subsequently submerged in either Caesalpinia or Hoffmannseggia, is treated here as a distinct genus and the North American species are revised. This revision provides a key, corrected nomenclature, new combinations, and descriptions for all North American species. One new species is described and distribution maps are provided for each of the nine species.Billie L. Turner Plant Resources Cente

(Vol. 03, 2000-12) Hoffmannseggia Humilis, The Correct Name for H. Gladiata (Fabaceae)

In order to correct an error in the recently published revision of Hoffmannseggia in North America, the correct nomenclature for H. humilis is provided.Billie L. Turner Plant Resources Cente

Note on Ailurus fulgens

Volume: 1869Start Page: 507End Page: 50

(Vol.17, 2014-12) The Role of Allotriploidy in the Evolution of Meconopis (Papaveraceae): A Preliminary Study of Ancient Polyploid and Hybrid Speciation

Also known as the Himalayan Poppy, Meconopsis is a genus of herbaceous plants growing only in the high elevation habits of the Himalaya and its adjacent plateau and mountain areas. The genus exhibits high morphological and ecological diversity, but the major causes of divergence in Meconopsis have not previously been studied. Our recent revised taxonomic classification, based on a molecular phylogeny, divided the genus into four monophyletic sections. Because chromosome number varies among these sections and our previous phylogenetic analyses revealed extensive incongruence between the recovered nrITS and cpDNA trees, possibly due to ancient hybridization, this study focused on evaluating the potential role of ancient polyploidization and hybridization in Meconopsis’ evolutionary history. Our investigation based on the results of reconstructed ancestral chromosome numbers using a Maximum Likelihood method implemented in chromEvol showed that two extant Meconopsis sections (sect. Grandes and sect. Primulinae) shared a triploid ancestor. We further examined the pattern of hybridization in Meconopsis by reconstructing a nuclear marker GAPDH (glyceraldehyde 3-phosphate dehydrogenase gene) network. The result, along with morphological, phylogenetic, and cytological evidence, all point to a hybrid nature of the triploid ancestor. Based on the resultant GAPDH network, an ancient reticulate evolution scenario in Meconopsis is proposed. Overall, this preliminary study shows how an ancient triploid event promoted polyploid evolution in Meconopsis and also exemplifies how allotriploidization and successive polyploidization played an important role in diversification of the genus.Billie L. Turner Plant Resources Cente

(Vol.18, 2015-12) Phylogenetic Analysis of Meconopsis (Papaveraceae) and Evaluation of Two Controversial Taxonomic Species

Meconopsis is a genus native to the high elevation habitats that range from the western Himalaya eastward to the Hengduan Mountains (China). The genus has been the subject of several taxonomic treatments and monographs by generations of botanists, which has led to a long and confusing taxonomic history with inconsistent species concepts and conflicting interpretations of relationships among named taxa. In the present study, we reconstructed the evolutionary history of Meconopsis utilizing four chloroplast markers (rbcL, matK, ndhF and the trnL-trnF intergenic spacer) and the nuclear ribosomal internal transcribed spacer (nrITS). Incongruence found between the cpDNA and nrITS trees was investigated to detect reticulate evolution, using the approximately unbiased (AU) method. Based on the evolutionary patterns revealed by our resultant phylogenies, we evaluated the species delimitations of the two most controversial “species” (Meconopsis horridula and Meconopsis napaulensis) in the genus and the inconsistency among their previously published treatments. As a result, we provide taxonomic suggestions for these species that include the proposal of a M. horridula species complex.Billie L. Turner Plant Resources Cente

Data from: A new infrageneric classification of Meconopsis (Papaveraceae) based on a well-supported molecular phylogeny

Meconopsis is an herbaceous genus native to the high altitude habitats across the Himalaya and adjacent plateau and mountain areas. Attractive Meconopsis flowers have spurred many European botanists to study the taxonomy of the genus resulting in numerous infrageneric classifications, dating from the first taxonomic revision in the late 19th Century until the most recent monograph in 2014. All, however, were morphology-based treatments and largely inconsistent with one another. To investigate the incongruence among the previous taxonomic grouping strategies of the species in Meconopsis and settle the controversies, we employed a well-resolved molecular phylogeny built by analyzing four chloroplast markers (trnL-trnF intergenic spacer, matK, ndhF, and rbcL). We found that the evolutionary relationships revealed by our phylogeny disagreed to varying degrees with any infrageneric relationship suggested by previous authors. Therefore, we propose a revised classification based on our phylogenetic topology as well as the morphological and cytological patterns reflected by the phylogenetic structure. To achieve a practical and approachable system, we have tried to retain as much as possible of phylogenetically meaningful components from previous taxonomies for the genus. As a result, we used the four major clades of our Meconopsis phylogeny as the bases for infrageneric sections (Meconopsis sect. Meconopsis, M. sect. Aculeatae, M. sect. Primulinae, and M. sect. Grandes). A key to the sections is provided, followed by a description and composition of each

Floral Rewards: Alternatives to Pollen and Nectar

Volume: 68Start Page: 301End Page: 32