Volume 82 - Issue 1 (March 2017)

Seed Production and Germination of Penstemon oklahomensis Pennell (Plantaginaceae), a Southern Great Plains Endemic

ABSTRACT We investigated the seed production and germination requirements of Penstemon oklahomensis, a species of conservation concern, to determine interannual variation in seed production and germination requirements. Mature seed capsules were collected and seed numbers counted in two successive years to assess interannual variation in seed production. A significant difference in number of seeds produced was found between collection years. Germination trials were conducted using the seed collected and subjected to three stratification treatments in two soil types. Seeds held over from the first collection year were also germinated to investigate viability loss a year after collection. Survival analysis was used to estimate the probability of seed germination under the treatment conditions. Germination probability was highest for seeds that underwent a cold stratification period of 60 days if sown the same year as they were collected, regardless of soil type used. Seeds held over a year had higher germination probability

Read / Download Full Article »

Propagation by Cuttings of the Federally Threatened Apios priceana (Fabaceae)

ABSTRACT Apios priceana (Fabaceae) is a rare herbaceous perennial vine. Seed collection for ex situ conservation is difficult because seed production is sporadic. We investigated propagation by cuttings of A. priceana at Redstone Arsenal, Alabama. Two experimental factors were investigated: donor plant size (small vs. large) and month of cutting (May vs. June 2013). We also documented impact of cutting collection on donor plants by recording size and reproductive variables from both cut and uncut (control) plants. About one-third of cuttings formed tubers by May 2014; success did not differ due to donor plant size or month of cutting. However, May cuttings produced two-fold more tubers and had five-fold greater total tuber mass. Large donor plants grew more, and produced significantly more inflorescences and legumes than small donors. Cutting treatment alone did not significantly affect any donor plant variable, showing that donor plants recovered quickly after cuttings were taken. Significant

Read / Download Full Article »

Reviewer Acknowledgement: Castanea Reviewers for 2016 (82-1)

The Editorial Committee gratefully acknowledges and thanks the following  people who reviewed manuscripts for Castanea during 2016. CASTANEA REVIEWERS FOR 2016 Rob Addington Mac H. Alford T. Wayne Barger Craig Barrett Vanessa Beauchamp Z. Carter Berry Jay F. Bolin Robert Boyd Gloria Caddell Joshua W. Campbell Julian Campbell Matt Candeias Brandi Cannon Richard Carter Xiongwen Chen Lawrence J. Davenport Alan R. Franck Scott B. Franklin John Freudenstein Cecil Frost Paul Gagnon Donald Hagan Rebecca E. Hale Ryan Huish Sean E. Jenkins Suneeti Jog Diana D. Jolles Wesley M. Knapp Karen Kuers Claude Lavoie Nancy Loewenstein Urbatsch Lowell Lucas C. Majure Paul McKenzie Conley K. McMullen John McNeill Nicole Miller-Struttmann Wayne Morris Howard S. Neufeld Priscilla Nyamai Michael W. Palmer Derick B. Poindexter Christopher P. Randle Donald G. Ruch Tom Saladyga Michael Schafale Gerald F. Schneider Alfred Schotz Scott Schuette Victor Shelburne Michael Simanonok Mark Skinner R. Wayne Tyndall Donald Walker Lisa

Read / Download Full Article »

Indirect Effects of Landscape Spatial Structure and Plant Species Richness on Pollinator Diversity in Ozark Glades

ABSTRACT: Changes in landscape spatial structure—specifically, reductions in habitat area and connectivity—are thought to be a primary cause of pollinator declines across North America. However, the mechanisms by which landscape structure influences pollinator diversity are not well understood. Because flowering plants and pollinators are generally mutualistic, the impact of landscape structure on one can influence the diversity of the other directly or indirectly. Here, we examine the direct and indirect effects of landscape structure on plant and pollinator communities in the naturally patchy, dolomite glade grasslands of the Missouri Ozarks. We quantified landscape spatial structure and the richness of plants and flying invertebrate pollinators in 30 glades. Higher pollinator diversity was not directly related to greater landscape area and connectivity. However, we found evidence for an indirect relationship where better-connected landscapes support higher plant richness, which in turn supports greater pollinator diversity. Our findings highlight the importance of conserving extensive,

Read / Download Full Article »

North and South: Morphological Variability in the Endangered Opuntia cespitosa in Canada and Variation with Environmental Conditions

ABSTRACT Opuntia cespitosa (until recent taxonomic splitting, identified as O. humifusa) is an endangered cactus in Canada, is found in only two populations nationwide after some local extirpations. The larger site is at Point Pelee National Park (PPNP-ON) at the northern edge of its range has little published data. Data were collected for plant size, overlying cover (the species is sensitive to high shade), reproductive variables, and various cladode (pad) characteristics to assess response to local conditions. The PPNP-ON population was considered conspecific to many populations throughout the eastern USA until recently. A southern Humifusa clade population in Florida was sampled to confirm the recent separation of these populations into distinct species. A variety of parametric (e.g., ANOVA) and nonparametric (chi-square, Spearman’s correlation) tests were used to determine relationships across variables. This study contributes to our foundational knowledge of an endangered species. Results for this species in its last major

Read / Download Full Article »

Ectomycorrhizal Fungi Associated with American Chestnut at a Site in Tennessee, USA

ABSTRACT The ectomycorrhizal fungi associated with American chestnut (Castanea dentata) were characterized using DNA extracted from the root-tips of naturally occurring saplings from a forest in northeastern Tennessee. A total of 18 taxa were recorded, although one of these (Oidiodendron maius) was surprising because it has been reported previously to form what appear to be mycorrhizal associations only with members of the Ericaceae. One-third of the recorded taxa were representatives of the genera Russula or Lactarius (both members of the family Russulaceae), and three other genera (Cortinarius, Tomentella, and Tricholoma, each represented by two species). The data presented herein at least suggest that members of the Russulaceae are among the most common and widespread ectomycorrhizal fungi associated with naturally occurring individuals of American chestnut in the forests of eastern North America in which it was once dominant. However, it should be pointed out that our data are limited and thus

Read / Download Full Article »