Date of Award

1996

Degree Name

Biological Sciences

College

College of Science

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Dan K. Evans

Second Advisor

Donald C. Tarter

Third Advisor

Jagan V. Valluri

Abstract

Elements of the Scutellaria ovata complex in the eastern United States are reported to include S. ovata var. pseudoarguta, S. ovata var. rugosa, S. ovata var. virginiana and S. ovata ssp. ovata. All but S. ovata ssp. ovata occur in the shale barren habitat of eastern West Virginia and western Virginia. S. ovata var. pseudoarguta has been proposed as a threatened element in North America. A morphometric study of specimens collected in West Virginia, Virginia and Ohio was undertaken to determine which characters are most useful in separating taxa in the complex. Nineteen characters were assessed from 104 herbarium specimens and the data subjected to principal component analysis, canonical discriminant analysis and Duncan•s model of analysis of variance. Specimens were grouped according to collection site in order to investigate intrapopulation and interpopulation variation. The results of this part of the study showed significant differences between western West Virginia and Ohio material and plants collected in eastern West Virginia and western Virginia. Variation between sites in West Virginia and Virginia was minimal. Plants were also grouped taxonomically according to variety or subspecies. The statistical procedures showed plant height, leaf length and width, petiole length, internode length, stem width and leaf cordateness to be the best characters for separating the subcomplex S. ovata var. pseudoarguta - S. ovata var. rugosa from S. ovata var. virginiana and S. ovata ssp. ovata. The latter taxa are separated by leaf width, floral bract length and width, first internode length, raceme length and raceme internode length. S. ovata var. pseudoarguta and S. ovata var. rugosa were shown to be very similar morphologically and separate only by leaf pubescence. Studies incorporating electrophoretic protein profiles were also carried out in order to analyze biochemical differences among members of the S. ovata complex. Taxa included in the morphometric study were examined along with a single population of Scutellaria elliptica Muhl., which was used as an outlier species. One dimensional SDS-Polyacrylamide gelelectrophoresis was used to separate soluble leaf proteins from 40 specimens representing four taxa. lntrapopulation and interpopulation variation was assessed as was variation within and between taxonomic groups. The results showed a high degree of homogeneity within the complex and the outlier element. Some differences were seen between taxa and populations, but variation was inconsistent and not significant enough to justify taxonomic separation based on protein profile data.

Subject(s)

Lamiaceae - West Virginia.

Lamiaceae - Virginia.

Lamiaceae - Ohio.

Download

Share

COinS