Noteworthy Collection: Maryland, Tennessee, and North Carolina
Noteworthy Collection: Maryland, Tennessee, and North Carolina
Amaranthus pumilus Raf. (Seabeach amaranth) was rediscovered on Assateague Island by the senior author on 3 August 1998, 31 years after the last known specimen was collected on 8 August 1967 by E.A. Higgins (MARY, s.n.!). Assateague Island is a 50-km island beginning at Ocean City Inlet in Worcester County, Maryland, and ending at Chincoteague Inlet in Accomack County, Virginia. Ocean City Inlet was stabilized by jetties after its formation by a 1933 hurricane; Chincoteague Inlet has not been stabilized. The National Park Service has managed the Maryland portion since 1965, with the exception of a small State park, and the U.S. Fish and Wildlife Service has managed the Virginia portion (all within Chincoteague National Wildlife Refuge) for migratory waterfowl since 1943.
ABSTRACT
Herbaceous zones in a Carolina bay in Maryland (Delmarva Bay) were monitored annually during 1987-97 by fixed-point photography and by sampling peak percent cover of each species in permanent plots during years of sufficient drawdown. The peripheral Panicum hemitomon zone of 1987 became dominated in 5 years by Acer rubrum (red maple) and Liquidambar styraciflua (sweet gum) with mean peak percent cover increasing from 22% to 88%. Live P. hemitomon cover decreased from 80% to 1%, and Rhexia virginica disappeared from sampling plots. Since the P. hemitomon population did not expand or migrate toward the center of the bay, this zone could be replaced by forest. Another peripheral zone, dominated in 1987 by Rhynchospora charalocephala, also was overtaken by red maple and sweet gum; Rhexia virginica all but disappeared from the zone; and this zone likewise could become forested. The central zone was dominated throughout the study by Scleria reticularis, R. virginica, Lachnanthes caroliniana, and Panicum verrucosum. Although the relative cover of central zone species changed from year to year, a significant trend in absolute percent cover did not occur over the 11-year period. However, in ecotone plots of the central zone and the P. hemitomon zone, R. virginica decreased significantly while red maple and sweet gum increased significantly, thus indicating that afforestation of peripheral communities is already affecting the central zone. Woody plant establishment is probably related to very low rainfall during the winters of 1984-85 and 1985-86 and summers of 1986 and 1987. Once established, subsequent flooding conditions were insufficient to kill saplings and small trees. Studies are needed to understand the potential contribution of farm irrigation wells, regional drainage ditches, and a contiguous pine plantation to bay afforestation. In addition, knowledge of the historic role of Amerindian fires in the Delmarva Bay ecosystem could be helpful in better understanding natural vegetation dynamics.
ABSTRACT
A year long survey in 1995 provided an overview of the vegetation of a 25.5 ha montane longleaf pine tract on Fort McClellan, a United States Army Post adjacent to Anniston, Alabama. The location in northeast Alabama is close to the elevational limit of the longleaf pine ecosystem. Military maneuvers caused a fire presence to be maintained over time, resulting in the maintenance of this rare peripheral system. However, fire presence had declined from historic frequency, and the forest type was changing from a longleaf pine to a mixed pine-hardwood type. The vegetational survey added to baseline data on the tree components of the tract. The survey identified 146 vascular plant species from 53 families.
ABSTRACT
The vascular flora of a 12 ha successional prairie in Jasper County, Illinois was studied during the growing season of 1996. Abundance and flowering dates (initial, peak, and final) were determined for most of the species. Also, frequency (%), average cover, and importance value (IV = 200) of the taxa were determined using randomly located quadrats along line transects through the area. One hundred forty-four taxa were observed in the prairie, 35 monocots and 109 dicots, of which 20 were woody species and 10 introduced exotics. Andropogon gerardii (big bluestem) had the highest IV (44.97) followed by Cassia fasciculata (partridge pea), Euthamia graminifolia (grass-leaved goldenrod), Schizachyrium scoparium (little bluestem), Eleocharis intermedia (spike rush), and Solidago nemoralis (field goldenrod).
ABSTRACT
During late summer 1998, we studied 30 plots at sites on the previously inundated shoreline of Cave Run Lake, a flood-control reservoir in east-central Kentucky. Among the sites, four shoreline elements were identified: riparian forests (n = 4), sheltered banks (n = 6), flats (n = 8), and exposed banks (n = 12). Of the 167 plant species collected, 14% were Obligate Wetland species, 21% were Facultative Wetland species, 22% were Facultative species, 27% were Facultative Upland species, 5% were Obligate Upland species, and 11% were Not Categorized. Thirteen species (8%) occurred in 15 or more of the plots and 62 species (37%) were single-plot occurrences. Riparian forests had the highest representation of Obligate and Facultative Wetland species; Obligate Upland and Not Categorized species occurred most frequently on exposed banks. Flats had highest species richness and exposed banks had lowest species richness. Among all sites, increasing slope was associated with decreasing species richness. Maintenance or loss of the soil profile as influenced by slope and exposure clearly established the relative conservation value of different shoreline elements. Optimal management of these sites in the future will require consideration of flood schedules and site-specific trends (e.g., tree invasion).
ABSTRACT
Ludwigia uruguayensis is known to comprise a decaploid entity (L. hexapetala) and a hexaploid one (L. grandiflora, including the type of L. uruguayensis), but the two chromosomal races differ only by quantitative, intergrading morphological features, a large portion of their genome is hypothesized to be shared, and they are known to produce hybrids of intermediate morphology in regions of sympatry. Ludwigia hexapetala is the more common, but both occur in the southeastern United States. We agree in general with earlier studies regarding the nature of the distinction between the two entities but suggest that a more reasonable treatment of them would be as subspecies within a single species: L. grandiflora subsp. grandiflora and L. grandiflora subsp. hexapetala, comb. et stat. nov.
ABSTRACT
The genus Lindernia All., as treated here, is represented in the New World by fourteen species. Six species are members of the Section Brachycarpae, five of which are postulated to be native in the New World. One native and one introduced species are in each of the sections Lindernia and Tittmannia. Old World introductions also include two species in Section Torenioides and one species each in sections Numularia and Bonnaya. Keys are provided to the fourteen species and four varieties that occur in the New World. Descriptions and distribution maps are included for the native taxa and most of the introduced species, and most are also illustrated. Nomenclatural changes include a new variety and new combinations for a species and a variety. Lindernia viscosa is reported for the first time in the New World.
ABSTRACT
The generic names Martiusia Schult., Nauchea Descourt., Ternatea Tourn. ex Mill., Vexillaria Eaton, and Vexillaria Raf. are synonyms of Clitoria L. The name Clitoria pinetorum McFarlin is a synonym of Clitoria fragrans Small. The name Clitoria serrulata B.G. is a synonym of Clitoria ternatea L. var. ternatea. The names Clitoria borealis Transleau & P.E. Williams and Clitoria umbellata Transleau & P.E. Williams are rejected names.