Noteworthy Collections: Maryland, Virginia, South Carolina, Alabama, and Georgia
Noteworthy Collections: Maryland, Virginia, South Carolina, Alabama, and Georgia
Noteworthy Collections: Maryland, Virginia, South Carolina, Alabama, and Georgia
Scientific Note: A Red-Fruited Nuphar advena (Nymphaeceae) From Virginia
ABSTRACT The Ohio distribution, current state status and habitats of twenty-eight taxa of the genus Carex (Cyperaceae) are described. Three species and one hybrid are additions to the Ohio flora: Carex alopecoidea, C. longii, C. lucorum, and C. ✕subimpressa. Four species may be deleted from the Ohio flora: Carex baileyi, C. gravida, C. merritt-fernaldii, and C. ormostachya.
ABSTRACT Many researchers stress the importance of nutrient limitation on barrier island plant communities. The accreting north end of Hog Island, part of the Virginia Coast Reserve-Long Term Ecological Research site, provided an opportunity to quantify amounts of plant biomass along a natural dune chronosequence (24, 36, 120+ yr-old dunes) and biomass response to experimental additions of nitrogen. In a one-year study, nitrogen addition increased plant biomass, with greater allocation to shoots than roots. In response to nitrogen fertilization, soil nitrogen increases were greatest on the oldest site while biomass increases were smallest. Naturally occurring NO2- + NO3- availability increased with age across the chronosequence. Aboveground biomass was inversely proportional to nitrogen availability and decreased from younger dunes to the oldest. Nitrogen does not appear to be the major limiting factor along the chronosequence. Groundwater hydrographs suggest the oldest dune may be moisture limited.
Book Review: A Guide to Wildflowers in Winter
ABSTRACT Phytoplankton species composition and cell concentrations were determined from samples taken during an ongoing bloom of the toxic dinoflagellate Gymnodinium breve that occurred in November 1987 in North Carolina Core Sound and coastal waters. Despite G. breve concentrations that reached 3.27 x 10^5 cells L-1, this was not a monospecific bloom. Total phytoplankton abundance increased regardless of G. breve concentrations. Principle components analysis and multiple regression analyses identified taxa showing positive and negative associations with G. breve. Phytoplankton with increased concentrations during this bloom included the diatoms Actinoptychus senarius, Odontella aurita, Rhizosolenia stolterfothii, and the dinoflagellates Ceratium furca, C. teres, Katodinium rotundatum, Prorocentrum minimum, Protoperidinium divergens, and Scrippsiella trochoidea. Decreasing in abundance during this bloom were several Cyclotella spp., Triceratium favus, Gymnodinium sp., and Oscillatoria erythraea.
ABSTRACT Thirty-three [17.0-58.7 cm diameter] white, southern red, and scarlet oaks of dominant or suppressed crown position on two sites were inoculated at 1.4 m above ground level with mycelia of either of two isolates of Phytophthora cinnamomi in late July, 1994. Six months later the inoculated areas were debarked and observed for canker development. Cankers formed around mycelial plugs in 100% of the trees. Mean canker length/width for all species was 43.6/4.3 cm. From these observations, it appears that these species are very susceptible to this soil-borne pathogen. However, naturally occurring cankers on oaks have not yet been reported in the United States even though P. cinnamomi is common in southern Appalachian soils where these oak species are abundant.
ABSTRACT An open Lebanon limestone cedar glade complex with abundant Grindelia lanceolata was sampled to determine frequency and life form of associated vascular plant taxa, and density of reproductive and nonreproductive plants of G. lanceolata, a short-lived monocarpic perennial. Species with >50% frequency in the 85 1 m x 1 m sample plots were G. lanceolata (100%), Sporobolus vaginiflorus (96.5%), the cedar glade endemic Dalea gattingeri (91.8%), Ruellia humilis (64.7%), Isanthus brachiatus (63.3%), and the cedar glade endemic Pediomelum subacaule (56.5%). Forty-four of the 54 taxa in the 85 plots had a frequency of ≤20%. More than 75% of the taxa are hemicryptophytes (40.7%) or therophytes (35.3 %). Only 11.0 % of the 4,164 plants of G. lanceolata counted had flowered. The G. lanceolata type is a vegetation unit of open cedar glades that has received little attention.
ABSTRACT Vegetation-substrate relationships of a sandstone outcrop located along the Ohio River are presented. Dominant species were crustose lichens (Endocarpon pusillum Hedw., Psorotichia schaereri (Massal.) Arnold, and Rinodina oxydata (Massal.) Massal.), Panicum virgatum L., and Amorpha fruticosa L. Five dominance types were identified from cluster analysis based upon composition of cryptogams and vascular plants: 1) Atrichum angustatum (Brid.) B.S.G.-Hypericum prolificum L., 2) Amorpha fruticosa-Panicum virgatum, 3) Ulmus rubra Muhl., 4) Endocarpon pusillum-Psorotichia schaereri, and 5) Rinodina oxydata. Discriminant-function analysis identified five important substrates in the dominance type structure on the outcrop: 1) dripway rock, 2) talus rock, 3) bare rock, 4) rock depression, and 5) loess soil. Disturbance from river flooding, degree of shading, and aspect are thought to maintain the vegetation.