Volume 65 — Issue 3 (Sept 2000)

New and Noteworthy Records of Carex (Cyperaceae) from Kentucky

ABSTRACT Eleven species and one subspecies are reported as new or noteworthy to the flora of Kentucky. Carex cherokeensis Schweintz, Carex reniformis (L. Bailey) Small, and Carex seorsa Howe are reported for the first time. Significant increases in distribution are reported for Carex abscondita Mackenzie and Carex socialis Mohlenbrock & Schwegman. Additional records and/or updates of historical records include Carex aestivalis M. A. Curtis, Carex alata Torrey, Carex appalachica Webber & Ball, and Carex leptonervia (Fernald) Fernald. Previously reported but without cited vouchers, the occurrence of Carex atlantica L. Bailey subsp. capillacea (L.Bailey) Reznicek, Carex crebriflora Wiegand, and Carex longii Mackenzie are now verified.

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Microhabitat Study of Lotus unifoliatus var. helleri: Microdistribution, Associated Species, and Potential Effects of Roadside Mowing

ABSTRACT Lotus unifoliatus var. helleri (Carolina Birdsfoot Trefoil), is a candidate rare taxon of the Piedmont in North Carolina. The distribution of individuals in a Rowan County population was clumped. The abundance of individuals, their height, cover, and fruit production were negatively related with occurrences of Dichanthelium scoparium, Panicum anceps, and Liquidambar styraciflua. A field experiment indicated no significant effect of opening size in grassy vegetation on trefoil seed germination, survivorship, average height, and fruit production. A field clipping study suggested that roadside mowing prior to flower initiation may not reduce survivorship or fruit production to levels below those of unmowed plants.

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Symbiotic Seed Germination of an Orchid in Decline (Platanthera integra) from the Green Swamp, North Carolina

ABSTRACT In vitro symbiotic seed germination of the yellow fringeless-orchid, Platanthera integra (Nuttall) Gray ex Beck, is reported. Seeds of P. integra collected from the Green Swamp (Brunswick, County, North Carolina) were inoculated with mycorrhizal fungi (Epulorhiza spp.) isolated from the root-like organs of three southeastern orchids: Platanthera ciliaris (L.) Lindley, P. integrilabia (Correll) Luer, P. integra. All fungi promoted seed germination, and leaf-bearing seedlings were obtained using the fungus from P. integrilabia. Seeds exposed to prolonged (1 and 2 hr) scarification followed by white light pretreatment (12 hr: 12 hr; L:D) yielded a higher percentage of leafless seedlings (protocorms) compared to standard techniques. We advocate the widespread preservation of existing orchids and their habitats in order to safeguard mycor- rhizal fungi for use in conservation.

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Vegetation and Ground Water Alkalinity of Betsch Fen, a Remnant Periglacial Fen in South Central Ohio

ABSTRACT Betsch Fen is a 14 ha fen in south central Ohio and is among the largest and least disturbed periglacial fens of the region. Of the 107 taxa of vascular plants recorded during surveys conducted in 1994-96 only five were non-native, and those five were found predominantly in the riparian forest which bordered the fen proper. Significant populations of eight state-listed species were present (Carex tenera, Carex trichocarpa, Filipendula rubra, Gentiana procera, Parnassia glauca, Potentilla fruticosa, Sanguisorba canadensis, and Solidago ohioensis) as well as populations of the rare spotted turtle (Clemmys guttata) and the Baltimore checkerspot butterfly (Euphydryas phaeton). A narrow band of riparian forest bordering a stream divides Betsch fen into two fen areas. The northern fen was covered by sedge meadow in which Carex stricta was the dominant. In contrast, the southern fen included areas of open marl flat typified by Juncus brachycephalus, Rhynchospora capillacea, and Scirpus

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Natural Hybridization Between Rhododendron periclymenoides and R. atlanticum Relative to Herbivory by Pyrrhalta rufosanguinea

ABSTRACT The goals of this study were to document natural hybridization between Rhododendron periclymenoides and R. atlanticum and to assess its significance relative to herbivory by Pyrrhalta rufosanguinea, a leaf beetle believed to be monophagous for R. periclymenoides. Populations of the Rhododendron species and a putative hybrid swarm were compared using a mixture of quantitative morphological and micro-molecular characters. Herbivory in parental and hybrid populations was estimated in cafeteria style host-choice experiments. Principal components analysis and discriminant analysis suggested bidirectional introgression in the hybrid population. Feeding levels were significantly higher for putative introgressants to R. periclymenoides than for introgressants to R. atlanticum. In the hybrid population, percent leaf area eaten by the beetles was positively correlated with leaf size and concentrations of the flavonoid asebotin and its aglycone, but negatively correlated with glandular trichome density and the concentration of myr- icentin 3-0-rhamnoside. Two hypotheses regarding the evolutionary significance of natural

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