Botany Commons^™

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson

Publications (WR)

The response to periodic desiccation of periphyton communities developed in eddy environments or in areas exposed to variable, direct current was examined. Algal communities were incubated on clay tiles for between 2 and 12 weeks in the Colorado River, directly below Hoover Dam from October, 1983 - January, 1984. Mean daily discharge from the dam decreased over this period. To assess the influence of these discharge changes on community dynamics, samples collected over the first 12 weeks of the investigation were compared to samples of the same age collected over the final 8 weeks.

The small diatom taxon Achnahthes spp …

Ua66/6 Brigadoon Nature Preserve Survey Phase I, Wayne Mason, Jeff Jenkins, Kenneth Nicely, Herbert Shadowen

WKU Archives Records

A preliminary report of an ongoing survey on the mammals, birds, vascular plants, and fungi that have been recorded at the Brigadoon Nature Preserve from November, 1983 - September, 1984.

Phenotypic Differences In Populations Of Euonymus Americanus L. From The Central United States & Autecological Studies Of This Species In A Deciduous Forest Of Kentucky, Paul Bayer

Masters Theses & Specialist Projects

The concentrations of sodium and potassium in the leaves of Euonymus americanus collected from a relict hardwood forest during a four month period showed a possible winter conditioning pattern. Seeds collected from this same relict stand would not germinate, even though they were subjected to a wide variety of germination experiments. Phenotypic differentiation in fully developed leaves was not found; however, differences related to the length of the growing season were noted. Autecological studies of Euonymus americanus should be continued to investigate the role of this plant in relict hardwood stands.

An Ultrastructural Study Of Transmitting Tissue Development In The Pistil Of Lilium Leucanthum, Stanley R. Gawlik

Biology Faculty/Staff Publications

A study of developing transmitting tissue of Lilium Leucanthum pistils was undertaken in order to correlate structure with function. Lining the stylar canal are stigmatoid cells which contain a secretory zone consisting of a labyrinth of wall ingrowths characteristic of transfer cells. The functional feature of the labyrinth is a high surface-to-volume ration that facilitates an intensive transmembrane flux of solutes. Stigmatoid cells in various stages of development and maturation have been investigated with the aid of electron and light optics in conjunction with cytochemical techniques. During the development of the secretory zone, vesicles, formed by hypersecretory dictyosomes, fuse with …

Seasonal Shifts Of Photosynthesis In Portulacaria Afra (L.) Jacq., Lonnie J. Guralnick, Patricia A. Rorabaugh, Zac Hanscom

Arts & Sciences Faculty Publications

Portulacaria afra (L.) Jacq., a perennial facultative Crassulacean acid metabolism (CAM) species, was studied under natural photoperiods and temperatures in San Diego, California. The plants were irrigated every fourth day throughout the study period. Measurements of ¹⁴CO₂ uptake, stomatal resistance, and titratable acidity were made periodically from July 1981 through May 1982. P. afra maintained C₃ photosynthesis during the winter and the spring. Diurnal acid fluctuations were low and maximal ¹⁴CO₂ uptake occurred during the day. The day/night ratio of carbon uptake varied from 5 to 10 and indicated little nocturnal CO₂ uptake. CAM …

Inflorescence Architecture And Evolution In The Fagaceae, Robert B. Kaul, Ernst C. Abbe

School of Biological Sciences: Faculty Publications

First paragraph:

Inflorescence architecture is receiving increasing attention with respect to its role in the life of plants, but much remains to be learned of its effects on pollination and dispersal biology (see Wyatt, 1982). Little is known of the biology of fagaceous inflorescences or of their relationships with the growth or the reproductive patterns of the trees. Most studies (Abbe, 1974; Macdonald, 1979; Fey & Endress, 1983) have concentrated on the nature of the flower clusters (often called dichasia or partial inflorescences) and cupules. Hjelmqvist (1948) and Soepadmo (1972) briefly reviewed the variety of inflorescences in the Fagaceae. Čelakovský …