Harperella (Ptilimnium nodosum) is a federally endangered plant species with a large population along Sideling Hill Creek, Allegany and Washington Counties, Maryland. Monitoring of this species is difficult owing to the unpredictable flood events that change the distribution and composition of stream substrates of its rocky shoal habitat. We characterized substrate types in 80 quadrats using two methods of nonmetric multidimensional scaling (NMS and MDS). We employed multiple-response permutation procedure (MRPP) to examine differences in substrate composition between habitats occupied (N  =  52) and unoccupied (N  =  28) by Harperella. The NMS and MDS ordinations show that Harperella cover and amount of fine sediments are positively associated. Harperella occupies specific microhabitat with high cover of fine sediments, often held in crevices of exposed bedrock. The MRPP results demonstrated that substrate composition in occupied versus unoccupied habitats differ significantly. This difference is chiefly attributable to cover of fine sediments in occupied habitats and cobble, gravel, and sand in unoccupied habitats. We conclude that the local distribution and abundance of Harperella patches in Sideling Hill Creek is constrained by the abundance of appropriate substrate microhabitat in any given year and recommend that annual census be modified to focus on large persistent patches.

Effective conservation requires an understanding of the genetic interactions among populations and individuals of a species, particularly those with fragmented, isolated distributions. Alnus maritima (seaside alder) is a rare tree species with an extremely fragmented distribution of highly isolated populations in the Delmarva Peninsula, Georgia, and Oklahoma. We conducted a mating system study to estimate the outcrossing rate, inbreeding coefficient, biparental inbreeding rate, and correlation of paternity in progeny from a Georgia and an Oklahoma population to investigate the effects of isolation on the A. maritima mating system. Data from nine microsatellite loci showed similarly high multilocus outcrossing rates in both populations (t_m  =  0.94). Individual tree outcrossing rates were also high (t_m  =  0.873–1.047). There was no significant biparental inbreeding in either population, but there was significantly higher correlated paternity in the Oklahoma population. Results showed the high outcrossing expected for a wind-pollinated, monoecious species that can promote the maintenance of genetic variation detected in A. maritima seed pools and standing populations. Likewise, pollen flow among Oklahoma populations may promote maintenance of regional genetic variation. However, despite the genetic diversity in the seed pool generated by A. maritima's highly outcrossed mating system, failure of new individuals to be recruited into populations from seed presents an obstacle that will need to be considered when developing conservation strategies for this rare species.

An invasion by Phellodendron amurense Rupr. (Amur corktree) provided an opportunity to examine the subsequent changes in the forest composition that took place since the invasion began. Through the removal of 278 individual trees of P. amurense, tree ring analysis allowed a re-creation of the forest over the 46 yr since the species first arrived at the site. This analysis shows that P. amurense demonstrates the ability to invade additional areas and, over time, increases both its relative density and relative dominance. Through an analysis of both living and standing dead individual trees, P. amurense appears to be poised to continue its gradually increased influence over the forest. This highlights the need for better recognition of the species as an invasive plant, and a more vigorous effort to control existing invasions.

The University of Mississippi Field Station is a 300-hectare area located in the Eocene Hills of the interior coastal plain of the southeastern US. Twenty long-term monitoring plots were established in 1996 following a major ice storm. Plots were sampled for understory (vegetation less than 1.5 m height) vegetation from 1996 to 2008 to study the changes in vegetation due to natural disturbance and to study the spread of invasive species. Species richness, total percent foliar cover, total percent open space and importance values (based on frequency and cover) were determined. Results indicate that there are 345 vascular plant species belonging to 90 families at the University of Mississippi Field Station (UMFS). Poaceae was the most abundant family followed by Asteraceae and Fabaceae. Understory species richness increased from 73 in 1996 to 195 in 2008. Mean percent foliar cover decreased from 58% in 1996 to 32% in 2008. Importance values for the invasive species Microstegium vimineum and Lonicera japonica decreased in 2008. Native species such as Andropogon virginicus and Vitis rotundifolia became dominant in 2008. Thus, there was a shift in vegetation with native species becoming more prevalent and displacing invasive species.

A study of seed coat micromorphology, using both light microscopy and scanning electron microscopy, revealed characters of taxonomic significance and utility among the species of Eriocaulaceae of the United States and Canada. Our survey of nine native species of Eriocaulon, five Lachnocaulon, and one Syngonanthus revealed diversity in the shape and size of the cells of the seed coat, the degree and pattern of ornamentation, and appendage shape. In the context of world Eriocaulaceae, the species of the United States and Canada exhibit no morphologies that are unique.

Floras, or documented lists of vascular plant species in a defined area, are widely used in biodiversity research and conservation, and represent a common type of publication in regional botanical and natural history journals. Although all floras present common types of information, there has not yet been a formal attempt to develop community standards for floristic data. As a consequence, published floras often lack basic data describing the study area, taxonomic sources, and criteria for inclusion of species. Here, we develop a grading scheme for floras and apply it to 145 articles in 5 leading journals (Castanea, Rhodora, Sida/Journal of the Botanical Research Institute of Texas, Journal of the Torrey Botanical Club, and Southeastern Naturalist) published from 2000 through 2009. We found that the average ‘grade’ was 80%, and did not vary among journals. We also list common mistakes and confusions. We urge authors, editors, and reviewers to adopt (and adhere to) a set of standards that we provide, or to develop similar comprehensive standards of their own.

The Kokiwanee (56 ha) and Hathaway (29 ha) preserves are located in northeastern Indiana. Both sites include gorges cut by tributaries of the Wabash River, which produce a range of microenvironments that are unusual for this part of Indiana. Floristic inventories were done from 2004 through 2011. Kokiwanee had 467 vascular plant species, while Hathaway had 316. A total of 529 species, representing 325 genera and 104 families, were found in the two sites combined, with 254 species being found in both. Many of the 213 species found only at Kokiwanee occurred in mature forest on a southwest-facing bluff or in fens; most of the 62 species found only at Hathaway were found in a crop field, old fields, or an east-facing gorge wall. Forty-three percent of the species found were county records. Nineteen percent of species were exotic, a significantly lower proportion than for the state as a whole. One state threatened-list species (Dactylorhiza viridis) and three state watch-list species (Liparis loeselii, Panax quinquefolius, and Veratrum woodii) were found. A number of species are near their northern range limits at these sites. Floristic quality is relatively high.

Analyses of nuclear ribosomal DNA have suggested the paraphyly of Syringa with respect to Ligustrum, a hypothesis requiring further testing from other sources of data. In addition, relationships among lineages of Syringa have not been resolved. In this study, we used DNA sequences of two nuclear and five plastid regions to better resolve phylogenetic relationships of Syringa and Ligustrum. Our results support the derivation of Ligustrum from within Syringa, thus the paraphyly of Syringa. Six series are recognized in Syringa and their relationships are: (Syringa, (Pinnatifoliae, (Ligustrae, (Ligustrina, (Pubescentes, Villosae))))). Subgenus Syringa as traditionally defined is paraphyletic, containing subgenus Ligustrina. The Syringa pubescens complex may be paraphyletic with S. pubescens more closely related to the Syringa pinetorum complex than to other species of its own complex. Our estimated times of divergence suggest that series of Syringa have diversified in the middle Miocene (9.65–17.67 mya), each with unique morphology.

Lepraria caesiella as currently circumscribed includes two sets of populations with different thallus morphologies. The populations are chemically identical but differ ecologically and are rarely sympatric. A phylogeny was inferred from ITS1, 5.8S, and ITS2 sequence data generated from a geographically broad sampling of the populations with each thallus type. Two strongly-supported clades were recovered that correlate to the two different morphotypes present within the species. Thus, L. caesiella is restricted to populations with aggregate thalli. Populations with placodioid thalli are formally described herein as a new species, L. harrisiana. A detailed taxonomic treatment of both taxa is presented.

Kosteletzkya pentacarpos (L.) Ledeb. (syn.  =  Kosteletzkya virginica (L.) C. Presl ex A. Gray) has been treated as a single variable species or as a species including four varieties: K. virginica var. althaeifolia, var. aquilonia, var. smilacifolia, and var. virginica. The aim of this study was to test the validity of formally recognizing these putative infraspecific taxa with a statistical analysis of morphological data. Loans were received from 15 herbaria, for 1,114 specimens; 224 were selected. Measurements were taken from these 224 specimens for 42 characters and analyzed by canonical discriminant analysis, which recognized two dimensions. Var. smilacifolia and var. aquilonia were separated from the other two groupings and correctly predicted at 100%. Var. smilacifolia is morphologically distinct from the other taxa in having linear hastate leaves with reflexed linear lobes, an unbranched inflorescence, a slender stem, and a mostly entire leaf margin. A new combination is proposed: Kosteletzkya pentacarpos (L.) Ledeb. var. smilacifolia (Chapm.) S.N. Alexander. All other former putative infraspecific taxa are synonymous with Kosteletzkya pentacarpos var. pentacarpos.