Accurate mapping, inventory assessment, and habitat descriptions are critically important for the development of plant conservation strategies of rare plants. Georgia plume, Elliottia racemosa (Ericaceae), is a rare threatened plant endemic only to the state of Georgia. In this study, census and distribution data were collected and the ecological habitat characterized for all known populations of georgia plume using geographic information system/global positioning system (GIS/GPS)-based methods. Causes for population losses and decline were assessed by evaluating both extant populations and historically reported but currently inactive sites. Landowner permission was obtained to visit 56% (32 of 57) of all known recorded populations. Over 40% of visited locations no longer contained georgia plume; 58% of inactive sites were associated with anthropogenic disturbances including farming and timber. Populations not visited by ground were evaluated using aerial photographs: of 29 putative populations, 66% were judged highly unlikely to contain georgia plume based on current land use. Census data verified that many populations have few individuals: 75% contained less than 45 individuals; over one-third contained 12 or fewer individuals. Over 80% of extant populations had an area of less than 0.3 ha. Field and aerial assessments of recent and historically noted populations confirm that georgia plume has disappeared from many previously reported locations and that fewer than two dozen populations may remain.
Justin A. Porter, David Berle and Hazel Y. Wetzstein
Noelle J. Fuller, Ronald B. Pegg, James Affolter and David Berle
The use of medicinal plants in the United States is increasing. Holy basil (Ocimum tenuiflorum L. and Ocimum gratissimum L.), a medicinal herb native to India, has become increasingly popular for its therapeutic benefits. Traditionally, holy basil has been used to promote longevity by reducing stress and restoring balance to the body. Because it is easy to grow and adapts to a wide range of growing conditions, there is great potential for holy basil production in the southeastern United States. The purpose of this study was to evaluate holy basil varieties for harvestable weight and essential oil content. Fourteen varieties of holy basil were grown during the 2015 and 2016 seasons and compared. The main active compound in the holy basil essential oil fraction, eugenol, was quantitated and compared for each variety, because it is believed to be responsible for many of the health-promoting effects. Overall, there were significant differences in harvestable weights and essential oil yields among the varieties, and a significant effect of growing season. The eugenol content was highly variable among the varieties examined, with higher eugenol contents in 2016 than in 2015. The variety that had the overall highest yield, essential oil content, and eugenol concentration was PI 288779, a USDA accession, suggesting its use in future breeding research.
Justin A. Porter, Hazel Y. Wetzstein, David Berle, Phillip A. Wadl and Robert N. Trigiano
Georgia plume, Elliottia racemosa (Ericaceae), is a small tree endemic only to the state of Georgia, where it is listed as a threatened species. Information about genetic relatedness is critical for establishing approaches for safeguarding, reintroduction, and conservation of this rare species. The genetic relationships among and within selected georgia plume populations were evaluated using random amplified polymorphic DNA (RAPD) in conjunction with site visits at which time a census and GPS survey were conducted. Populations ranged from those containing eight to over 1000 individuals with most populations containing few plants (less than 50 individuals). With one exception, small populations with less than 50 individuals had more genetic similarity than populations with greater numbers of plants. Two protected populations containing large numbers of individuals were sampled extensively. Genetic similarity of individuals was not associated with plant proximity within a population. The small number of individuals and geographic isolation characteristic of many populations were associated with high within-population genetic similarity. Conservation priorities should be given to preserving as many different populations as possible to retain the genetic diversity of the species. Whether the narrow genetic variation found in some populations may be contributing to lack of sexual reproduction in the wild is an area for further study.