Welsh, Stanley L. (Rm 375 MLBM, Stanley L. Welsh Herbarium, Brigham Young University, Provo, UT, 84602 U.S.A.; stanley_welsh@byu.edu). Rupert C. Barneby and Pugillus Astragalorum. Brittonia 57: 301–313. 2005.— Rupert C. Barneby, his monumental contributions to the taxonomy of Astragalus and his place among American botanists, is discussed. His twenty contributions in the series Pugillus Astragalorum spanned fifteen years of his botanical development from an interested naturalist to an accomplished taxonomist in this extremely species-rich genus. Barneby's work on Astragalus culminated in the 1188 pages of the Atlas of North American Astragalus, which treated of 552 taxa and was published in 1964.

Estrada-C., A. E. (Facultad de Ciencias Forestales, Universidad Autónoma de Nuevo León, Apartado Postal 41, Linares, N.L. 67700, Mexico; aeduardoestradac@prodigy.net.mx), J. A. Villarreal-Q. (Departamento de Botánica, Universidad Autónoma Agraria Antonio Narro, Buenavista, Saltillo, Coahuila 25315, Mexico; javillarreal00@hotmail.com) & C. Yen-M. (Facultad de Ciencias Forestales, Universidad Autónoma de Nuevo León, Apartado Postal 41, Linares, N.L. 67700, Mexico; cyen100@hotmail.com). Astragalus mario-sousae (Fabaceae: Galegeae), a new species from northeastern Mexico. Brittonia 57: 314–319. 2005.—Astragalus mario-sousae is described from the central part of state of Nuevo León, Mexico. It differs from Astragalus esperanzae by its habit, peduncles, pedicels, and fruits.

Alexander, J. A. (Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, OR, 97331-2902, U.S.A.; alexandj@science.oregonstate.edu). The taxonomic status of Astragalus mokiacensis (Fabaceae), a species endemic to the southwestern United States. Brittonia 57: 320–333. 2005.—Astragalus mokiacensis has been a problematic species since it was first described in 1877. Every major revision delimited this taxon differently. A principal components analysis of morphological data from herbarium specimens was used to determine the affinities between type specimens and extant populations of A. mokiacensis. The taxon recently recognized as A. lentiginosus var. trumbullensis is morphologically similar to the lectotype of Astragalus mokiacensis. Astragalus lentiginosus var. trumbullensis is herein recognized as a low-elevation minor variant and considered a synonym of A. mokiacensis. A taxonomic key and complete synonymy are included.

Knaus, B. J. (Oregon State University, Department of Botany and Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331-2902, U.S.A.; knausb@science.oregonstate.edu), R. C. Cronn (USDA Forest Service Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR, 97331, U.S.A.; rcronn@fs.fed.us) & A. Liston (Oregon State University, Department of Botany and Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331-2902, U.S.A.; listona@science.oregonstate.edu). Genetic characterization of three varieties of Astragalus lentiginosus (Fabaceae). Brittonia 57: 334–344. 2005.—Astragalus lentiginosus is a polymorphic species that occurs in geologically young habitats and whose varietal circumscription implies active morphological and genetic differentiation. In this preliminary study, we evaluate the potential of amplified fragment length polymorphism (AFLP) markers to resolve infraspecific taxa in three varieties of Astragalus lentiginosus. Distance-based principle coordinate and neighbor-joining analyses result in clustering of individuals that is congruent with population origin and varietal circumscription. Analysis of molecular variance of two Oregon varieties demonstrates that varietal categories account for 11% of the total variance; in contrast, geographic proximity does not contribute to the total variance. AFLPs demonstrate an ability to discriminate varieties of A. lentiginosus despite a potentially confounding geographic pattern, and may prove effective at inferring relationships throughout the group.

Jerry M. Baskin (Department of Biology, University of Kentucky, Lexington, KY, 40506-0225, U.S.A.; jmbask0@uky.edu) & Carol C. Baskin (Department of Biology, University of Kentucky, Lexington, KY, 40506-0225, U.S.A.; ccbask0@uky.edu and Department of Plant and Soil Science, University of Kentucky, Lexington, KY, 40546-0321, U.S.A.). Ecology of two geographically restricted Astragalus species (Fabaceae), A. bibullatus and A. tennesseensis, of the eastern United States. Brittonia 57: 345–353. 2005.—Astragalus bibullatus is endemic to limestone glades in the Central Basin of Tennessee, and except for one population in Illinois, A. tennesseensis is endemic to limestone glades in the Central Basin and in the Moulton Valley of Alabama. However, A. tennesseensis has been extirpated from four counties in Illinois, from its only known site in Indiana, from one county in Tennessee, and from one county in Alabama. Astragalus bibullatus is closely related to the geographically widespread Great Plains taxon A. crassicarpus var. crassicarpus (section Sarcocarpi), whereas A. tennesseensis is the only taxon in section Tennesseensis. Both species are shallow-rooted, hemicryptophyte perennials without vegetative reproduction, have no effective means of seed dispersal, form long-lived seed banks, have similar life cycle phenologies, are intolerant of heavy shade, and have moderate amounts of genetic diversity. Much additional information is available on the autecology of A. tennesseensis. Its primary habitat is the transition zone between open glades and glade woods, where physical environmental factors are intermediate between those of the adjacent zones. Seedling-juvenile survival is low. Plants flower first in their second to fifth year and only a few times before dying, are self-incompatible, respond to drought by shedding leaves and by accumulating large amounts of proline, and compete poorly. Populations exhibit high fluctuations in number of individuals and have high turnover rates. A greenhouse study of A. bibullatus and A. crassicarpus var. crassicarpus did not identify any difference in responses of these species to light or soil moisture that could account for the great differences in geographic ranges. Thus, historical factors were also considered to explain the narrow endemism of A. bibullatus. Finally, we present previously unpublished data on the effect of light level and of competition with the cedar glade dominant Sporobolus vaginiflorus in several watering regimes on growth of A. tennesseensis. The role of these factors in restriction of this species to its transition zone microhabitat is discussed.

Scherson, R. A. (Section of Evolution and Ecology, University of California, Davis, CA 95616, U.S.A.; rascherson@ucdavis.edu), H.-K. Choi (Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A.; hchoi@ucdavis.edu), D. R. Cook (Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A.; drcook@ucdavis.edu) & M. J. Sanderson (Section of Evolution and Ecology, University of California, Davis, CA 95616, U.S.A.; mjsanderson@ucdavis.edu). Phylogenetics of New World Astragalus: Screening of novel nuclear loci for the reconstruction of phylogenies at low taxonomic levels. Brittonia 57: 354–366. 2005.—This study explores methods to use information gathered from genomics technology to understand evolutionary relationships in the hyperdiverse legume group Neo-Astragalus. These species inhabit deserts and mountains of North and South America, and even though the monophyly of the group is well established, relationships within it are still poorly understood. Plastid genes, commonly used to infer phylogenies in plants, are usually not useful for closely related taxa because of low levels of genetic variation. The Medicago truncatula genome project provided a suite of candidate nuclear loci with high levels of variation that might prove suitable for low-level phylogenetics. This paper reports the development of methods for screening a large number of these nuclear loci, and detailed analysis of four of them. Four different patterns of phylogenetic diversification occur in the loci sampled from these genomes of Astragalus species. One locus (CNGC4) was single copy and could be directly used in phylogenetic analyses. Two loci (ARG10 and FENR) showed patterns strongly suggestive of duplication events in some taxa, and one locus (tRALS) has apparently undergone a cryptic duplication, making it very difficult to diagnose. Potential methods for using the information provided by these loci are discussed.

Kazempour Osaloo, S. (Department of Plant Biology, Tarbiat Modares University, Tehran 14115-175, Iran; skosaloo@yahoo.com), A. A. Maassoumi (Department of Botany, Research Institute of Forests and Rangelands, Tehran 13185-116, Iran) & N. Murakami (Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan). Molecular systematics of the Old World Astragalus (Fabaceae) as inferred from nrDNA ITS sequence data. Brittonia 57: 367–381. 2005.—This study represents a nuclear rDNA ITS-based phylogenetic analyses of a greater sampling of the Old World Astragalus compared to our previous work (212 vs. 134 taxa). Phylogenetic relationships among 212 species (213 accessions) of the Old World Astragalus, including newly segregated monotypic genus Podlechiella, the two aneuploid New World Astragalus, and five related genera, were inferred from analyses of nuclear rDNA ITS sequences using maximum parsimony. A total of 658 nucleotide sites and four binary characters for indels were analyzed. The results of phylogenetic analyses suggest sect. Phyllolobium, comprising mostly the Chinese species, is placed outside of the so-called Astragalus s. str. and is a well-supported monophyletic group. The monotypic annual segregate genus Thlaspidium (≡Astragalus sect. Thlaspidium, A. thlaspi), is clearly nested within Astragalus s. str. Among the many sections analyzed here, only sects. Cenanthrum, Caraganella, Eremophysa, Incani, Laxiflori, and Lotidium are strongly supported as monophyletic. Our analysis, in agreement with previous studies, shows that the North American euploid Astragalus species are scattered throughout the Old World groups of the genus.

Wojciechowski, M. F. (School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, U.S.A.; mfwojciechowski@asu.edu). Astragalus (Fabaceae): A molecular phylogenetic perspective. Brittonia 57: 382–396. 2005.— Nucleotide sequences of the plastid matK gene and nuclear rDNA internal transcribed spacer region were sampled from Astragalus L. (Fabaceae), and its closest relatives within tribe Galegeae, to infer phylogenetic relationships and estimate ages of diversification. Consistent with previous studies that emphasized sampling for nrDNA ITS primarily within either New World or Old World species groups, Astragalus, with the exception of a few morphologically distinct species, is strongly supported as monophyletic based on maximum parsimony and Bayesian analyses of matK sequences as well as a combined sequence dataset. The matK data provides better resolution and stronger clade support for relationships among Astragalus and traditionally related genera than nrDNA ITS. Astragalus sensu stricto plus the genus Oxytropis are strongly supported as sister to a clade composed of strictly Old World (African, Australasian) genera such as Colutea, Sutherlandia, Lessertia, Swainsona, and Carmichaelia, plus several morphologically distinct segregates of Eurasian Astragalus. Ages of these clades and rates of nucleotide substitution estimated from a fossil-constrained, rate-smoothed, Bayesian analysis of matK sequences sampled from Hologalegina indicate Astragalus diverged from its sister group, Oxytropis, 12–16 Ma, with divergence of Neo-Astragalus beginning ca. 4.4 Ma. Estimates of absolute rates of nucleotide substitution for Astragalus and sister groups, which range from 8.9 to 10.2 × 10⁻¹⁰ substitutions per site per year, are not unusual when compared to those estimated for other, mainly temperate groups of papilionoid legumes. The results of previously published work and other recent developments on the phylogenetic relationships and diversification of Astragalus are reviewed.

McMahon, M. M. (University of California, Davis, One Shields Avenue, Davis, CA, 95616, U.S.A.; mmmcmahon@ucdavis.edu). Phylogenetic relationships and floral evolution in the papilionoid legume clade Amorpheae. Brittonia 57: 397–411. 2005.—Amorpheae (Fabaceae: Papilionoideae) was first considered a natural group by Rupert Barneby in his illustrated monograph Daleae Imagines. Amorpheae currently comprise eight genera, ca. 250 spp., and extensive floral diversity, including loss of corolla and addition of a stemonozone. The Amorpheae and many of Barneby's subtribal groups are supported as monophyletic by previous phylogenetic analysis of nuclear ribosomal and chloroplast sequence data. However, some relationships remain unclear. A nuclear marker derived from a genomic study in Medicago, CNGC4, was sequenced in selected Amorpheae. This is one of the first applications of this marker for phylogenetic study. The new data confirm some relationships inferred using trnK and ITS, but also provide evidence for new arrangements. Combined data were used to explore several aspects of Barneby's taxonomic framework. The phylogeny, in concert with data on floral morphology, implies that simplification of the complex papilionoid flower has occurred several times in the history of the Amorpheae.