This is the first documented reporting of pineland golden-aster (Pityopsis aspera var. adenolepis) in Maryland.
The quarterly newsletter of the Southern Appalachian Botanical Society from 1993 - present
An occasional collection of papers published by the Southern Appalachian Botanical Society.
This is the first documented reporting of pineland golden-aster (Pityopsis aspera var. adenolepis) in Maryland.
Twenty-four growing seasons after installation, five regeneration cuts and one understory control treatment were remeasured to assess long-term effects on stand composition and development in the Appalachian forest region of southwest Virginia. The six experimental treatments included understory control, group selection, high-retention shelterwood, low-retention shelterwood, leave-tree, and clearcut, plus a non-harvested control. Two-hectares of each treatment were replicated on three oak (Quercus) dominated sites in the ridge and valley physiographic province of southwestern Virginia in 1994 and 1995. Overall, results indicated the high-retention shelterwood treatment favored oak species and partially suppressed yellow poplar (Liriodendron tulipifera). Among the overstory removal treatments, the clearcut treatments accrued the greatest aboveground biomass, partially due to the greater yellow poplar component. The clearcut also contained a relatively high importance values for oak species, but the prevalence of faster growing species within the clearcut suggests that intermediate treatments, such as crop tree release, could be necessary to retain the oak component. Overall, the high-retention shelterwood represents a balance to passively control post-harvest composition to favor an oak component while accruing biomass without intermediate oak release treatments.
Kalmia latifolia, the mountain laurel, contains dangerous diterpene grayanotoxins, which make all parts of the plant toxic. Human consumption of honey made from Kalmia and Rhododendron nectar, so-called ‘mad honey,’ can result in serious poisoning. Despite this, homeopathic Kalmia latifolia tincture is available for purchase online. Here, we test a concentrated Kalmia latifolia tincture produced in the laboratory against a commercially available homeopathic Kalmia latifolia tincture. To evaluate outcomes, we treat Daphnia magna with these tinctures and evaluate changes to mortality, heart rate, and the differential expression of several genes related to detoxification and stress response. We find that the concentrated Kalmia latifolia tincture contains cytotoxic compounds beyond the ethanol solvent alone. This is evidenced by lower heart rates in daphnids 24 hours after treatment, and by the upregulation of Hsp90, a stress response gene, when compared to other treatment types. However, ethanol alone was found to cause higher mortality at both 24 and 48 hours than either Kalmia based tincture. We believe, despite poor solubility, some level of the hydrophobic grayanotoxins dissolve in the ethanol solvent used to create the distillation and are present in the final concentrated tincture making the final tincture likely far less potent than one performed using a strong organic solvent. Ethanol is a poor solvent for grayanotoxins and the final level of cytotoxins in the concentrated tincture is likely quite low. We find relatively little evidence for acute cytotoxicity in daphnids exposed to a concentrated Kalmia latifolia tincture.