Degree Name

Master of Science (MS)

Semester of Degree Completion

1993

Thesis Director

John E. Ebinger

Abstract

A study of the ecology, breeding systems, and pollinators of Spiranthes magnicamporum Sheviak was undertaken in fall 1992. An initial survey of three glacial drift hill prairies revealed sexual activity in this species via removed pollinia. Two hill prairie populations were used for pollination study. In each population, five individuals were randomly selected and crossed using autogamic, geitonogamic, and xenogamic methods. In addition, ten individuals were fitted with pollinator-exclusion bags. After capsule formation, all plants were harvested. They were examined in the lab for general morphology, the presence or absence of embryo formation, and the prescence of sexual or asexual characteristics. Samples were stained in order to determine the condition of the embryo(s) present. Asexual taxa of S. magnicamporum display adventitious polyembryony (agamospermy) while sexual taxa (autogamy) produce monoembryonic seeds. It was determined in both populations that for the most part, the breeding system exhibited was autogamy. Although no direct observations were made, it must be assumed that some pollination must be taking place due to the presence of removed pollinia.

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