Book Review: Women Botanists of Ohio Born Before 1900
Book Review: Women Botanists of Ohio Born Before 1900
Book Review: Women Botanists of Ohio Born Before 1900
Noteworthy Collections: South Carolina
ABSTRACT Three populations of Leersia lenticularis Michx. were located in western Ohio in 1991. All sites are within the floodplain of the St. Marys River, a tributary of the Maumee River and the Lake Erie basin. These stations are the first known for this species from the Great Lakes drainage. The Maumee Terrace, formed by overflow waters from prehistoric Lake Maumee, is a possible avenue of plant migration from the Mississippian drainage Wabash River into Lake Erie tributaries.
ABSTRACT Zigadenus densus and Z. leimanthoides are primarily southeastern Coastal Plain species, and both are rare in some parts of their range. Seeds have linear, underdeveloped embryos that are physiologically dormant; thus, they have morphophysiological dormancy. Cold stratification was the only requirement for embryo growth and dormancy break. Embryos in seeds of Z. leimanthoides grew from 0.43 to 2.47 mm in length during 9 weeks of cold stratification at 5°C. Nondormant seeds have a low temperature requirement for germination, and seeds that stayed at 5°C for 12 weeks began to germinate. In a nontemperature-controlled greenhouse, the first germination of seeds sown on 7 July was recorded on 28 December, at which time they had been exposed to 1,048 hours of cold stratifying temperatures (0-10°C). Germination in the greenhouse peaked between 2 January and 6 February, when mean daily maximum and minimum air temperatures were 10.9 and 3.0°C, respectively. In the
ABSTRACT Following three naturally ignited fires in the summer of 1986 on Cumberland Island National Seashore, Georgia, mature live oaks (Quercus virginiana), laurel oaks (Q. laurifolia), and red bays (Persea borbonia), were tagged to determine post burn survivorship. Amount of crown scorch evident after the fire was the best predictor of the condition of Quercus spp., while the degree of basal scorch was the best predictor of the condition of red bay 21 months later. Oak mortality was low. Although oaks which had completely scorched crowns usually did not survive (80% mortality), mortality for trees with 1 to 15% of their leaves surviving the fire was 43%. Of oaks with greater than 15% of their crown alive post burn, ten of 291 died and only six of these (2%) are likely to have been killed by fire induced damage. The results indicate that prescribed natural fire would probably cause little
ABSTRACT A twelve-month phytoplankton study was conducted in Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Four dominant phytoplankton groups were identified at these sites. These were the Bacillariophyceae, Cyanophyceae, Cryptophyceae and an autotrophic picoplankton component. Over the past 20 years there has been a decrease in the mean pH levels of Lake Drummond and the replacement of one its former major components, the Chlorophyceae, by the Cyanophyceae. Based on water quality analysis results and species diversity indices, Lake Drummond is classified as in an early eutrophic stage of development.
ABSTRACT The bryophytes of four habitats in South Carolina characterized by outcroppings of different rock types (i.e., gabbro, soapstone, granite, or diabase) were collected and identified. Slope, aspect, relative canopy closure, and dominant tree, shrub, and herb species were noted at each site. Soil pH and relative hardness of rock were also measured. Bryophyte species composition was compared among the four habitats in general, and site to site comparisons were made within comparable microhabitats (i.e., species on rock, trees, soil, or decaying wood). Although habitat and site differences were found, there appeared to be no obvious environmental factor to account for relationships between and distribution of species compositions.
ABSTRACT Previously, four hybrids have been known to occur naturally among certain members of the “rostrate” violets of Section Viola in the genus Viola. During examinations of herbarium specimens in a systematic study of the section, three new hybrids were found from the Appalachian region, two represented by a number of specimens from widely scattered localities. The morphology of all three is described, and two, V. appalachiensis ✕ striata and V. striata ✕ walteri are given the names V. ✕wujekii hybr. nov. and V. ✕cooperrideri hybr. nov., respectively. Low pollen viability and cleistogamous seed set are discussed. This constitutes the first report of interspecific hybridization involving V. appalachiensis Henry or V. walteri House.