Date of Award

1983

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

Abstract

The taxonanic relationship of Polemoniun reptans L. var. reptans and P. reptans L. var. villosum Braun (Polemoniaceae) is examined in this studly. The former taxon occurs throughout most of the eastern deciduous forest while the latter is rare and limited to southern Ohio and northcentral Kentucky. The natural coherence of the species has provided a bimodal frequency distribution which displays clustering of the two varieties at opposite ends of a continuum. Significant differences were obtained using the BMDP7M multivariate analysis (0.05 level of significance) based on morphometric information gathered from herbarium specimens throughout the midwest and eastern states, between var. reptans and var. villosum. Pubescence score, length and density of trichomes on the inflorescence and several floral characters provided sufficient dissimilarities for consistent identification of the two varieties. The data were also subjected to a Principle Component analysis which revealed a similar continuum between the varieties and an affinity with P. pulcherrimum. Calyx width, stigma length, petal width and length, pubescence score and cauline leaflet width and length carried the heaviest loading in separating cases. The pollen sculpturing of the P. reptans complex illustrates a sexine pattern more similar to P. micranthum than to P. pulcherrimum. Pollen viability of both varieties is relatively high (9o-95 percent) in natural populations. Cytological analysis determined a haploid chromosome number of nine (n = 9) for the P. reptans canplex and 18 (n = 18) for the polyploid P. vanbruntiae. A chromatographic examination of species-specific nitrogenous compounds in the vegetative material from populations of var. reptans and var. villosum revealed several constituents which were absent between the varieties while the populations showed identical fingerprints. Geographical, morphological and chemical differences exist which support the varietal status of both var. reptans and var. villosum.

Subject(s)

Polemonium -- Analysis.

Polemonium -- Varieties -- Testing.

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