Botany Commons^™

Notes On Neotropical Amanoa (Euphorbiaceae), W. John Hayden

Biology Faculty Publications

Lectotypes are designated for Amanoa caribaea Krug & Urban and A. guianensis Aublet; presumed syntypes of the latter taxon are shown to be heterogeneous by inclusion of a previously unrecognized species. Four new species of Amanoa are described: A. congesta from French Guiana and northeastern Brazil; A. gracillima from Manaus, Brazil; A. nanayensis from Amazonian Peru and adjacent Colombia and Brazil; and A. neglecta from French Guiana and Surinam. Amanoa sinuosa is proposed as a new name for the later homonym A. robusta Leal. A key to the 13 neotropical species is presented.

Methyl Salicylate Secretory Cells In Roots Of Viola Arvensis And V. Rafinesquii (Violaceae), W. John Hayden, John Clough

Biology Faculty Publications

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 …

Maine's Endangered And Threatened Plants, Maine State Planning Office

Maine Collection

Maine's Endangered and Threatened Plants

Executive Department, Maine State Planning Office, Critical Areas Program, 1990.

Fescues With Large Roots Are Drought Tolerant, H. A. Torbert, J. H. Edwards, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Consideration of root/soil interactions is essential in, adapting tall fescue (Festuca arundinacea Schreb.) to soil and climatic conditions of the Coastal Plain region of the southeast. Sandy soils of the region are very susceptible to the formation of hardpans. These compacted layers often restrict plant root development to the plow layer (0 to 6 in.) and prevent plant roots from reaching available moisture and nutrients in the subsoil horizons. Plants grown under these conditions are shallow rooted and will be subjected to water stress up to 50% of the time during the growing season. Although implements are available to penetrate …

Evaluation Of Seeding Rates Of Au Triumph And Endophyte-Infected Kentucky 31 Tall Fescue, Jeffrey F. Pedersen, D. M. Ball

Department of Agronomy and Horticulture: Faculty Publications

Increased difficulty in stand establishment of tall fescue (Festuca arundinacea Schreb.) has been reported by producers since the introduction of endophyte (Acremonium coenophialum Morgan Jones and Gams)-free tall fescue seed into the market place. This has encouraged the use of higher seeding rates for endophyte-free tall fescue without scientific basis. The objective of this study was to determine whether ‘AU Triumph’, and endophyte-free cultivar, and endophyte-infected ‘Kentucky 31’ differ in minimum seeding rates for successful establishment. Experiments were established at two locations in each of two years, using a randomized complete block with four replications. Soils at the two locations …

Heritability Of Root Characteristics Affecting Mineral Uptake In Tall Fescue, J. H. Edwards, Jeffrey F. Pedersen, R. C. Kingery

Department of Agronomy and Horticulture: Faculty Publications

Modification of plant roots can potentially increase the area. of adaptation of tall fescue (Festuca arundinacea Schreb.). Limited information is available on the heritability of root diameter and root volume in tall fescue. A greenhouse experiment was conducted with'50 random 'Kentucky 31' (Ky-31) tall fescue parents and their progeny grown in aerated nutrient solution during four separate time intervals. Measurements of root volume, root diameter, shoot Mg concentration, and shoot K/(Mg + Ca) ratio were made six weeks after clonal material was transplanted in nutrient solution. Heritability estimates for root volume, root diameter, shoot Mg concentration, and shoot K/(Mg …

A Review Of The Agronomic Characteristics Of Endophyte-Free And Endophyte-Infected Tall Fescue, Jeffrey F. Pedersen, G. D. Lacefield, D. M. Ball

Department of Agronomy and Horticulture: Faculty Publications

Agronomic differences between endophyte- (Acremonium coenophialum Morgan Jones and Gams) free and endophyte-infected tall fescue (Festuca arundinacea Schreb.) exist, and should be considered when implementing a management strategy. Although dry matter yield of tall fescue does not generally appear to be influenced by endophyte infection status, endophyte infection has been shown to improve seedling performance and survival, is associated with insect and nematode resistance, drought resistance, improved nitrogen assimilation, and higher seed set. Considering all biologically valuable characters of the endophyte-tall fescue relationship, survival of endophyte-infected tall fescue is probably better than that of endophyte-free tall fescue, especially in drought- …