Botany Commons^™

Plicate Staminal Filaments In Tillandsia Subgenus Anoplophytum (Bromeliaceae), T. M. Evans, Gregory K. Brown

Gregory K Brown

Plication of stamina!filaments is an important diagnostic character for Tillandsia subgenus Anoplophytum (ca. 45 species). The monophyletic integrity of subgenus Anoplophytum has recently been questioned, and we conducted an anatomical investigation of plicate stamina! filaments to better characterize this putative synapomorphy. Developmental studies show that the filament plications, or folds, become visible during or soon after anthesis. Serial sections of preplication filaments and filaments in sequential stages of plication were prepared and observed with light microscopy. A uniform sequence of parenchyma cell collapse begins three to four cell layers out from the vascular bundle and proceeds centrifugally to the epidermis. …

Changes In Plant Species Composition And Structure In Two Peri-Urban Nature Preserves Over 10 Years, Rebecca W. Dolan, Jessica D. Stepens, Marcia E. Moore

Rebecca W. Dolan

Peri-urban natural areas, at the boundaries of cities and adjacent agricultural/rural land, are subject to ecological threats endemic to both land use types. We used permanent plots to document changes in habitat quality by monitoring herbaceous-layer plant species presence and cover over a decade (1996/97 and 2007) in two peri-urban nature preserves in central Indiana, U.S.A. The preserves are comprised of different forest community types: wet-mesic depressional forest and mesic upland forest. Habitat characteristics, based on Floristic Quality Assessment parameters, showed only a single change for either preserve between survey years: wetness values were lower in the wet-mesic depressional site …

Two Hundred Years Of Forest Change: Effects Of Urbanization On Tree Species Composition And Structure, Rebecca W. Dolan

Rebecca W. Dolan

Despite their importance, the dynamics of urban floras are not well understood and quantitative historical data are rare. The current study used three data sets for trees in Indianapolis/Marion County, Indiana, U.S., to document change over 200 years to the original beech-maple forest and to examine future implications of contemporary tree planting efforts in light of these changes. Data on tree composition and size collected before significant settlement in the early 1800s are compared with recent surveys of trees in remnant natural areas and with trees found on city streets and rights-of-way. All the species recorded in historical surveys are …

Translocation In Tomato , Charles William Whitehead

Charles K Whitehead

No abstract provided.

The Effects Of Silica, Nitrogen, And Phosphorus Limitation On The Biochemical Composition Of Cyclotella Meneghiniana Kütz: An Experimental Analysis , David Fred Millie

David F. Millie

The effects of silica, nitrogen, and phosphorus limitation on the amount of cellular lipid, fatty acid, glucan, protein and chlorophyll of Cyclotella meneghiniana Kutz. were investigated in batch and semi-continuous culture experiments. In batch cultures, cells were removed from nutrient-replete media and resuspended in nutrient-deficient media according to a 2('3) factorial design in fractional replication. Cells were analyzed 3 and 9 days after transfer to treatment media. Of the 3 nutrients, only silica had a significant effect on a biochemical variable. Silica deficiency caused a significant increase (300%) in the amount of cellular protein. Cellular protein was also significantly different …

Lineage Sorting In Multihost Parasites: Eidmanniella Albescens And Fregatiella Aurifasciata On Seabirds From The Galapagos Islands, Jose L. Rivera-Parra, Iris I. Levin, Kevin P. Johnson, Patricia G. Parker

Patricia Parker