The woody flora of extreme southern Florida is dominated by species widespread in the West Indies and can bewilder botanists otherwise familiar with the southeastern United States. Visitors to the Florida Keys will see new familiar faces and will find this profusely illustrated, small (approximately 14✕21.5 cm) paperback book very useful for field identification.
An inexpensive book with readable and clear illustrations treating a difficult group of plants is indeed remarkable. The authors bring much experience and scholarship to this work on aquatics.
The aromatic roots of Viola arvensis and V. rafinesquii were studied in order to determine the chemical nature and anatomical localization of their volatile compounds. Gas chromatography and mass spectroscopy revealed a single detectable volatile compound, methyl salicylate. Light microscopy and differential staining with Sudan Ⅲ indicates the source of this compound to be enlarged secretory cells located in the endodermis, an unusual position for such cells in roots of angiosperms. The secretory endodermal cells are sporadic, but are more frequent in primary roots than in secondary roots and the lower portion of the hypocotyl. It is hypothesized that secretory endodermal cells are restricted within Viola to subgenus Melanium where the methyl salicylate confers protection against herbivores and/or pathogens.
The James River drains nearly a quarter of Virginia and traverses 483 km before entering the southern end of the Chesapeake Bay. It is the third largest tributary to the Bay. The river is tidal below the fall line and is bordered by wetlands. The present study examined tidal wetland floristics of four coastal plain counties along the lower James River. The study included nine sites: two estuarine emergent, three palustrine emergent, and four palustrine forested wetlands. Two hundred eighty-six species were found; 59 were previously unknown for one or more of these counties.
Floristically, the Yazoo-Mississippi Delta region is one of the poorest known areas in Mississippi. Recent field studies have yielded several state records, numerous Yazoo-Mississippi Delta region records, and other noteworthy collections that are reported herein. The flora of the rare ridge bottom forest is reported on, and certain species that are restricted to ridge sites and are rare in the Delta region are also discussed.
The results of an investigation into the distribution of the needle palm, Rhapidophyllum hystrix (Pursh) H. Wendl. & Drude, are presented here. This distinctive palm occurs sporadically in the southeastern United States and ranges from southcentral Florida to southern South Carolina, central Georgia, Alabama, and central Mississippi. Of the possibly 107 counties from which it is known, approximately one-half consist of a single population. Population sizes vary considerably and range from a single individual (either consisting of a single axis or multiple axes) to well over 1,000 individuals. Possibly up to 46 counties containing the needle palm have been added since the most recent treatment of Rhapidophyllum (22 counties are based on sight records or from the literature and hence are not documented with herbarium specimens); seven of these new county records were recently discovered by the senior author.
New specimens and continued studies have led to revisions of the Eastern North American Eubati, with 198 species now recognized. Several species recognized in former studies are reduced to synonymy.
Vascular plant communities in six Carolina bays in Maryland were classified using stratified-random plot sampling of presence and cover in conjunction with Bray-Curtis Polar Ordination and Sorensen’s Index of Dissimilarity. Species diversity and annual cover differences also were analyzed during the two-year study period of 1987-1988. Collectively, five zonal community types were identified in the ground layer. The most frequent type, dominated by Leucothoe racemosa Gray, was restricted to the forested perimeter. The Carex walteriana Bailey (C. striata Michx.) community occurred as an interlying zone near or contiguous with the forested perimeter and as the sole non-perimeter community. Panicum hemitomon Schult. only occurred as a narrow band near or adjacent to the forested perimeter. Rhexia virginica L. and P. verrucosum Muhl. communities were restricted to the innermost non-perimeter zone. Species diversity and annual differences in cover generally increased from perimeter to center. Leucothoe racemosa , P. hemitomon , and C. walteriana communities, restricted to drier portions of the gradient, had lower values for these parameters than the more mesic R. virginica and P. verrucosum communities.