Masters Theses

Frank Fusiak

Date of Award

6-1983

Degree Type

Thesis

Degree Name

Master of Science

Major

Botany

Major Professor

Edward E. Schilling

Committee Members

B. Eugene Wofford, Leslie G. Hickok

Abstract

A systematic study was conducted on the Prenanthes roanensis complex of the southern Appalachians. Investigations involving scanning electron microscopy, flavonoid chemistry, cytology and numerical taxonomy coupled with traditional taxonomic techniques were undertaken to evaluate species validity, limits and relationships, to determine if natural interspecific hybridization was occurring amongst members of this complex and to assess the endangered status of P roanensis.

With scanning electron microscopy, all taxa were determined to have pollen that was tricolporate and echinolophate and ligules that were transversely striate and distally rugose. With flavonoid analysis, a total of seven luteolin glycosides were isolated and characterized. Both scanning electron microscopy and flavonoid chemistry studies indicated that intraspecific differences were as great as interspecific differences. Meiotic analysis showed all individuals to be n = 8 with no irregularities. No species-specific characters could thus be discerned using these techniques.

Multivariate analyses were performed on 100 samples for 18 morphological characters. Cluster and principal coordinates analyses indicated that the samples can be divided into three groups that correspond to the eventually recognized species. These results from traditional taxonomic techniques and numerical analysis, especially those results derived from cluster analysis, support the recognition of the following three closely related but morphologically distinct species: P. altissima, P. roanensis and P. serpentaria.

The occurrence of natural interspecific hybridization could not be discerned from the aforementioned analyses. Its occurrence, however, cannot be conclusively ruled out at this time.

Lastly, P. roanensis should not be considered federally endangered or threatened. It is presently known from 20 counties in North Carolina, Tennessee and Virginia and is abundant at most of these sites that are federally protected public lands.

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