Luc Brouillet

Are many plant species paraphyletic

transforming widespread population systems through gene flow or selection, allopatric speciation by subdivision is likely to be less frequent than geographically local models of speciation. Low levels of gene flow will also increase the time required for the progenitor species to achieve monophyly. Thus, many plant species are likely to be paraphyletic, and predictably a species classification based on the criterion of monophyly is unlikely to be an effective tool for describing and ordering biological diversity.

Flora of North America North of Mexico

The Flora of North America north of Mexico treats all native and naturalized vascular plants and bryophytes in Canada, Greenland, St. Pierre et Miquelon, and the continental United States including the Florida Keys and Aleutian Islands (approximately 18 million square kilometers). It provides accepted names, literature citations, basionyms, synonyms, morphological descriptions, habitat, geographical distribution, conservation or weed status, and a discussion of taxonomic issues for approximately 20,000 species. Of the total 30 volumes anticipated, 18 have been published and one is in press, treating 2021 genera and 12,393 species. For the remaining volumes, 763 genera and 5,008 species have been submitted, and 82 of the 144 families have been submitted in full. Completion is anticipated by the end of 2017. The project is managed by the Flora of North America Association. Content from published volumes is available through eFloras and JSTOR and has been provided to the World Flora informatics team.

Phylogenetic position and biogeography of Hillebrandia sandwicensis (Begoniaceae): a rare Hawaiian relict

The Begoniaceae consist of two genera, Begonia, with approximately 1400 species that are widely distributed in the tropics, and Hillebrandia, with one species that is endemic to the Hawaiian Islands and the only member of the family native to those islands. To help explain the history of Hillebrandia on the Hawaiian Archipelago, phylogenetic relationships of the Begoniaceae and the Cucurbitales were inferred using sequence data from 18S, rbcL, and ITS, and the minimal age of both Begonia and the Begoniaceae were indirectly estimated. The analyses strongly support the placement of Hillebrandia as the sister group to the rest of the Begoniaceae and indicate that the Hillebrandia lineage is at least 51-65 million years old, an age that predates the current Hawaiian Islands by about 20 million years. Evidence that Hillebrandia sandwicensis has survived on the Hawaiian Archipelago by island hopping from older, now denuded islands to younger, more mountainous islands is presented. Various scenarios for the origin of ancestor to Hillebrandia are considered. The geographic origin of source populations unfortunately remains obscure; however, we suggest a boreotropic or a Malesian-Pacific origin is most likely. Hillebrandia represents the first example in the well-studied Hawaiian flora of a relict genus.

Selection of areas for protecting rare plants with integration of land use conflicts: A case study for the west coast of Newfoundland, Canada

Abstract On the west coast of Newfoundland (Canada) about 40% of the provincially rare plant species are not protected within the system of three national parks and two ecological reserves existing in the region. This study examines how heuristic algorithms can be used for selecting areas filling this gap while minimizing potential land use conflicts. One algorithm selected 78 areas of 1 km 2 each, representing the minimum set of areas that includes all species at least once. Only 13 out of these 78 areas were selected from existing protected areas; therefore, 65 would have to be added to this system to achieve full representation. A second algorithm reduced this number to 55 by seeking, from the beginning, only species not included in existing protected areas. A third algorithm constrained the choice of complementary areas to those that would have the lowest potential for conflicting land use (CLU). With this algorithm, however, full representation of rare plants within protected areas would need 79 areas instead of 55, i.e. trying to minimize the number of potentially conflicting areas entails selecting a significantly larger number of areas to achieve the same conservation goal. An index such as the CLU proposed here adds to the value of heuristic selection algorithms as indicative tools for planning a network of protected areas.

Phylogenetic relationships of American willows (Salix L., Salicaceae).

Salix L. is the largest genus in the family Salicaceae (450 species). Several classifications have been published, but taxonomic subdivision has been under continuous revision. Our goal is to establish the phylogenetic structure of the genus using molecular data on all American willows, using three DNA markers. This complete phylogeny of American willows allows us to propose a biogeographic framework for the evolution of the genus. Material was obtained for the 122 native and introduced willow species of America. Sequences were obtained from the ITS (ribosomal nuclear DNA) and two plastid regions, matK and rbcL. Phylogenetic analyses (parsimony, maximum likelihood, Bayesian inference) were performed on the data. Geographic distribution was mapped onto the tree. The species tree provides strong support for a division of the genus into two subgenera, Salix and Vetrix. Subgenus Salix comprises temperate species from the Americas and Asia, and their disjunction may result from Tertiary events. Subgenus Vetrix is composed of boreo-arctic species of the Northern Hemisphere and their radiation may coincide with the Quaternary glaciations. Sixteen species have ambiguous positions; genetic diversity is lower in subg. Vetrix. A molecular phylogeny of all species of American willows has been inferred. It needs to be tested and further resolved using other molecular data. Nonetheless, the genus clearly has two clades that have distinct biogeographic patterns.

Phylogenetic relationships among diploid species of Symphyotrichum (Asteraceae: Astereae) based on two nuclear markers, ITS and GAPDH.

The mostly North American subtribe Symphyotrichinae (Asteraceae: Astereae) comprises Canadanthus, Ampelaster, Psilactis, Almutaster, and Symphyotrichum. Intergeneric and interspecific relationships within the subtribe have been investigated in the past, particularly by Nesom [Nesom, G.L., 1994. Review of the taxonomy of Aster sensu lato (Asteraceae: Astereae), emphasizing the new world species, Phytologia 77, 141-297] and Semple [Semple, J.C., 2005. Classification of Symphyotrichum. Available from: ], using morphological and cytological approaches. Symphyotrichum is the largest and most complex genus within the subtribe and includes four subgenera: Symphyotrichum (x=7, 8), Virgulus (x=4, 5), Astropolium (x=5), and Chapmaniani (x=7). In this study we used two nuclear markers, the nrDNA internal transcribed spacer (ITS) and the low-copy nuclear gene glyceraldehyde 3-phosphate dehydrogenase (GAPDH), to resolve intergeneric and interspecific relationships within the subtribe at the diploid level, and to determine whether our phylogenies validate the classifications of Nesom or Semple. Our results confirm the distinct generic status of Canadanthus and Ampelaster, whereas Psilactis and Almutaster form a polytomy with Symphyotrichum. Within Symphyotrichum, subg. Virgulus is monophyletic based on ITS and appears polyphyletic based on GAPDH. Neither the ITS nor the GAPDH analyses support a distinct status for subg. Astropolium, which groups within subg. Symphyotrichum. In general, interspecific relationships within Symphyotrichum are unresolved. Lack of resolution may be interpreted as a case of recent and rapid evolutionary radiation.

PHYLOGENETIC IMPLICATIONS OF THE MULTIPLE LOSSES OF THE MITOCHONDRIAL coxII.i3 INTRON IN THE ANGIOSPERMS

Previous studies have shown that the mitochondrial coxII.i3 intron is absent in all rosids examined, in Philadelphus (Hydrangeaceae, Cornales), and in Catharanthus and Vinca (Apocynaceae, Gentianales). We surveyed for the presence or absence of this intron in 177 species representing all orders of angiosperms, where it is primitively present. The intron appears to have been lost independently in Gnetales, Laurales, Zingiberales, Ranunculales, Saxifragales, rosids, Santalales, Caryophyllales, Ericales, Cornales, Gentianales, Lamiales, Boraginales, Aquifoliales, Asterales, Dipsacales, as well as in the genus Escallonia. Depending upon the phylogenies used to interpret the losses, and due to lack of resolution in some groups, the intron could have been lost up to 27 times in the angiosperms (excluding the loss in Gnetales). The losses sometimes corroborate the monophyly of groups (rosids and Lamiales) or of subgroups within orders (in the Ranunculales, Caryophyllales, Cornales, Gentianales, and Asterales). In other groups, such as the Saxifragales, Ericales, and Dipsacales, the patterns of losses are more complex and would require further study. The presence or absence of the coxII.i3 mitochondrial intron seems a useful phylogenetic marker in some groups, but caution in interpretation is needed as multiple parallel losses have occurred throughout the angiosperms.

Numerical and Comparative Analyses of the Modern Systems of Classification of the Flowering Plants

The modern classifications of Cronquist, Dahlgren, Takhtajan, and Thorne have been compared with one another and also with those published at the beginning of the 20th century, which comprise the ones by Bessey, Engler, Gobi, and Hallier. Mantel and consensus tests have been used to compare the different matrices taken from the above classifications. Results indicate that all four modern classifications do not differ from one another statistically. Ordinal delimitation has not changed significantly for a century at least: Orders of the modern classifications are similar to those of the past classifications. However, the topology or structure of Cronquist’s and Takhtajan’s classifications differs from that of Bessey’s. Also, Engler’s dicotyledon classification is statistically different from those of the modern systems. Among past classifications, that of Hallier resembles the modern ones most. The resemblance among the modern classifications and, in general, with the past ones can be explained by the similarity in taxonomic principles and in the practice used. Two other factors help in explaining similarities among classifications: cognitive constraint and historical inertia. For instance, the Linnean scheme—upon which all botanical classifications are based—imposes on the latter a structure which allows only with difficulty and approximation the representation of taxon evolution. Moreover, not only have modern authors mutually influenced one another (particularly Cronquist/Takhtajan, Dahlgren/Thorne), but also they have been influenced by past authors. Indeed, modern classifications are a reshuffling of past ones. Also, Engler’s influence is great, especially at the ordinal level.For changes and modifications to become effective in future classifications of flowering plants, one will have to minimize, if not avoid, the implicit influence of the modern systems as standard systems, and to count on, among others, molecular data in redefining taxonomic concepts founded on classical morphology, and consequently to remove the prudence that makes us look at classification as a useful convention for which one of the basic criteria remains the stability of taxa recognized long ago.RésuméLes classifications modernes de Cronquist, Dahlgren, Takhtajan et Thorne sont comparées entre elles et avec les principales classifications du début du XXe siècle, celles de Bessey, Engler, Gobi et Hallier. Les tests de Mantel et de consensus ont été utilisés pour permettre la comparaison des différentes matrices tirées des classifications mentionnées ci-dessus. Les résultats des comparaisons montrent que les quatre classifications modernes ne diffèrent pas statistiquement entre elles. La délimitation des ordres n’a pas changé de façon significative depuis au moins un siècle: les ordres des modernes sont semblables à ceux des anciens. Toutefois, la topologie des classifications de Cronquist et de Takhtajan s’éloigne de celle de Bessey. La classification des Dicotylédones d’Engler diffère de celles des modernes. Parmi les classifications anciennes, celle de Hallier ressemble le plus aux modernes. La grande ressemblance des modernes entre eux et avec les anciens s’explique par la similarité dans les principes et l’approche taxonomique utilisés. Deux autres facteurs expliquent cette similarité: la contrainte cognitive et l’inertie historique. D’une part, la structure linnéenne qui fonde les classifications botaniques actuelles, impose aux classifications une rigidité qui permet difficilement la représentation de l’évolution des taxons. D’autre part, non seulement les auteurs modernes se sontils mutuellement influencés (surtout Cronquist/Takhtajan, Dahlgren/Thorne), mais ils ont été influencés par les anciens. Les classifications modernes sont en fait un remaniement des anciennes. De plus, l’influence d’Engler est forte, surtout au niveau de la délimitation des ordres.Les prochaines classifications des plantes à fleurs devront—pour que les changements se fassent sans contrainte — éviter l’influence implicite des systèmes modernes en tant que système-étalon, miser, entre autres, sur les données moléculaires pour redéfinir les concepts taxonomiques fondés sur la morphologie traditionnelle, et lever la prudence qui fait que l’on conçoit la classification comme une convention utile pour laquelle l’un des critères de base est la stabilité des taxons reconnus historiquement.

CHROMOSOME NUMBER DETERMINATIONS IN ASTER SECTION CONYZOPSIS (ASTERACEAE)

Chromosome numbers forAster brachyactis, A. frondosus, andA. laurentianus were determined to be 2n=14. The latter two are the first documented records for these taxa. The basic chromosome number for sectionConyzopsis is confirmed asx=7.

Microsatellite Markers of Willow Species and Characterization of 11 Polymorphic Microsatellites for Salix eriocephala (Salicaceae), a Potential Native Species for Biomass Production in Canada

Biomass produced from dedicated plantations constitutes a source of renewable energy and is expected to play an important role in several countries in the coming decades. The cultivation of woody crops such as willows therefore raises several environmental issues. In North America, several native willows are potentially interesting for biomass producers. Willow trees are diverse but few species used for environmental applications have been the object of molecular genetic studies. Based on the sequenced poplar genome, 24 microsatellite markers were assayed on five native North American willow species: Salix amygdaloides, S. discolor, S. eriocephala, S. interior and S. nigra. Polymorphic microsatellite markers were used to characterize the allele data on the shrub Salix eriocephala, a North American species with economic potential. Eleven markers amplified and confirmed the potential of this species. Analysis of samples from six populations in eastern Canada showed that all markers were variable as well as polymorphic in at least one population. The number of alleles per locus ranged from 1 to 9 (mean 2.95) and showed that these microsatellite markers can be used to assess genetic diversity of North American willow species.