Notes and News: Maryland, Virginia, West Virginia, Plant Systematics, and George
ABSTRACT Four species of ants are the principal dispersers of <em>Sanguinaria</em>, <em>Hepatica</em> and <em>Viola</em> diaspores in the Monongahela National Forest, West Virginia. They are <em>Aphaenogaster rudis</em>, <em>Formica subsericea</em>, <em>Myrmica punctiventris</em> and <em>Lasius alienus</em>. Variation in methods of diaspore presentation and diaspore characteristics, except for size, are not significantly reflected by ant species preferences for diaspore types, or by the frequencies with which different diaspores are removed by different ant species. However, there is a tendency for larger ant species to take larger diaspores and vice versa. The lack of specificity of the ant-diaspore interaction buffers the interaction against spatial and temporal heterogeneity.
ABSTRACT An extensive colony of <em>Asplenium heterochroum</em> was found growing on the 125 year old walls of the Yulee Sugar Mill, Yulee Sugar Mill State Historic Site, Homosassa, Citrus County, Florida. The extremely local and generally rare species normally grows on limestone rocks in woods or grottos and has never been recorded on man-made structures. It was found to be hexaploid (108 pairs at meiotic metaphase) and possessed fronds up to 37 cm in length (twice the stature of previously recorded North America collections).
ABSTRACT Quantitative studies of 27 relatively undisturbed hardwood forests in the central Coastal Plain of Virginia reveal that <em>Quercus alba</em>, <em>Fagus grandifolia</em>, <em>Liriodendron tulipifera</em>, and <em>Quercus falcata</em> dominate most stands. <em>Quercus alba</em>, <em>Q. falcata</em>, and <em>Liriodendron concerate</em> in separate margins of a Bray-Curtis ordination, while <em>Fagus</em> lies between <em>Q. alba</em> and <em>Liriodendron</em>, and broadly overlaps both. <em>Carya tomentosa</em>, <em>C. glabra</em>, and <em>C. cordiformis</em> concentrate in the same area as <em>Liriodendron</em>, and <em>Acer rubrum</em>, never very important, concentrates in the same area as <em>Quercus alba</em>. These forests were structurally more like the Southern Mixed Hardwood Forests of the southeastern Costal Plain, where <em>Fagus</em> is important, than the Oak-Hickory Forests of the Virginia Piedmont, where <em>Quercus coccinea</em>, <em>Q. rubra</em>, <em>Q. prinus</em>, and <em>Acer rubrum</em> are important.
ABSTRACT Distributions of Ohio’s native buckeye species, <em>Aesculus glabra</em> (Ohio buckeye) and <em>A. octandra</em> (yellow buckeye), were documented by collections from all parts of the state. <em>A. glabra</em> is associated with the Wisconsin and Illinoian drifts, and is restricted to outwash deposits and limestone bedrock areas beyond the limits of glaciation. <em>A. octandra</em> is confined to a part of the Unglaciated Allegheny Plateau, and to a westward extension across the state in the deeply dissected terrain bordering the Ohio River. The distribution of <em>A. glabra</em> is correlated with calcareous soils, and the distribution of <em>A. octandra</em> is inferred to be under the combined controls of topography and climates. Distribution maps, based on field records, are presented for the species in Ohio.
ABSTRACT Frequency of occurrence changes are cited for 69 non-indigenous plant taxa listed by Edwin L. Moseley in 1928. Of these taxa, approximately 38% are more frequent now (1978) than 50 years ago. Twenty-nine percent exhibit the same frequency of occurrence, while 33% are less frequent than they were 50 years ago. The number of non-indigenous taxa in the flora has increased from 10% to 18% during the past 50 years. Changes in the frequency of occurrence generally are brought about by changes in roadside habitats, railroad maintenance activities, and by construction of new residential communities.
ABSTRACT The substrate preferences of the lichens known from Maryland are listed and discussed. Substrate reversal is noted in <em>Alectoria</em>, <em>Cetraria</em>, <em>Hypogymnia</em>, <em>Parmeliopsis</em>, and <em>Umbilicaria</em>. Most of the species grow on deciduous trees; saxicolous species occur mainly on acidic rocks. State records are cited for 92 species.