This study involved a detailed study of the genus Taxus in Kentucky. A thorough examination was conducted, including a review of the literature, examination of field and herbarium specimens from both native and non-native species, microscopic analysis of leaf ultrastructure, chemical analysis of taxane content, and the construction of GIS models to predict the occurrence of the native species. In the review and examination of morphological features, it was found that the best features for separation of the taxa were plant height, the number of the rows of stomata per abaxial leaf band, and the location of papillose cells on the leaf epidermis. In particular, the SEM studies showed that stomatal bands are a reliable way of differentiating native and non-native Taxus species within Kentucky. A key to the taxa was prepared, as well as descriptions of the species. The chemical analysis failed to uncover any reliable differences between taxa utilizing only five taxanes. GIS models were prepared for 13 counties in eastern Kentucky, and these predicted the most likely occurrence of Taxus canadensis in each portion of the county. This study documented three species of Taxus that occur in Kentucky, T. baccata, T. canadensis, and T. cuspidata. Taxus canadensis is the only native species, considered to be a glacial relict, and is currently listed as a state threatened species. The other two species occur only rarely in nature as escapes from cultivation, likely from the spread of seeds by birds. There is no evidence of hybridization between native and non-native species. It was concluded that microhabitat requirements for T. canadensis are very restrictive, and that ongoing climate change may impact Kentucky's native population of T. canadensis.
","abstract_html":"<p>This study involved a detailed study of the genus Taxus in Kentucky. A thorough examination was conducted, including a review of the literature, examination of field and herbarium specimens from both native and non-native species, microscopic analysis of leaf ultrastructure, chemical analysis of taxane content, and the construction of GIS models to predict the occurrence of the native species. In the review and examination of morphological features, it was found that the best features for separation of the taxa were plant height, the number of the rows of stomata per abaxial leaf band, and the location of papillose cells on the leaf epidermis. In particular, the SEM studies showed that stomatal bands are a reliable way of differentiating native and non-native Taxus species within Kentucky. A key to the taxa was prepared, as well as descriptions of the species. The chemical analysis failed to uncover any reliable differences between taxa utilizing only five taxanes. GIS models were prepared for 13 counties in eastern Kentucky, and these predicted the most likely occurrence of Taxus canadensis in each portion of the county. This study documented three species of Taxus that occur in Kentucky, T. baccata, T. canadensis, and T. cuspidata. Taxus canadensis is the only native species, considered to be a glacial relict, and is currently listed as a state threatened species. The other two species occur only rarely in nature as escapes from cultivation, likely from the spread of seeds by birds. There is no evidence of hybridization between native and non-native species. It was concluded that microhabitat requirements for T. canadensis are very restrictive, and that ongoing climate change may impact Kentucky's native population of T. canadensis. </p>","abstract_has_math":false,"creators":["Pace, Robert Reed"],"institution":"Eastern Kentucky University","degree_name":"Master of Science (MS)","degree_level":"Master's","degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-01-01T08:00:00Z","date_published":"2015-01-01T08:00:00Z","updated_at":"2026-07-24T02:15:32Z","subjects":["Ecology","Habitat Modeling","Kentucky","Taxanes","Taxus canadensis","Plant Biology"],"languages":[],"rights":["Copyright 2015 Robert Reed Pace"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://encompass.eku.edu/etd/302","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Pace, Robert Reed"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Encompass Digital Archive, Eastern Kentucky University"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Master's"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Eastern Kentucky University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Ecology","Habitat Modeling","Kentucky","Taxanes","Taxus canadensis","Plant Biology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2015 Robert Reed Pace"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://encompass.eku.edu/etd/302"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study involved a detailed study of the genus Taxus in Kentucky. A thorough examination was conducted, including a review of the literature, examination of field and herbarium specimens from both native and non-native species, microscopic analysis of leaf ultrastructure, chemical analysis of taxane content, and the construction of GIS models to predict the occurrence of the native species. In the review and examination of morphological features, it was found that the best features for separation of the taxa were plant height, the number of the rows of stomata per abaxial leaf band, and the location of papillose cells on the leaf epidermis. In particular, the SEM studies showed that stomatal bands are a reliable way of differentiating native and non-native Taxus species within Kentucky. A key to the taxa was prepared, as well as descriptions of the species. The chemical analysis failed to uncover any reliable differences between taxa utilizing only five taxanes. GIS models were prepared for 13 counties in eastern Kentucky, and these predicted the most likely occurrence of Taxus canadensis in each portion of the county. This study documented three species of Taxus that occur in Kentucky, T. baccata, T. canadensis, and T. cuspidata. Taxus canadensis is the only native species, considered to be a glacial relict, and is currently listed as a state threatened species. The other two species occur only rarely in nature as escapes from cultivation, likely from the spread of seeds by birds. There is no evidence of hybridization between native and non-native species. It was concluded that microhabitat requirements for T. canadensis are very restrictive, and that ongoing climate change may impact Kentucky's native population of T. canadensis.
"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:source","label":"Dc Source","values":["Encompass Digital Archive: Online Theses and Dissertations"]},{"key":"dc:title","label":"Title","values":["The Status of the Genus Taxus In Kentucky"]}]}],"canonical_facts":{"dc:creator":["Pace, Robert Reed"],"dc:description.abstract":["This study involved a detailed study of the genus Taxus in Kentucky. A thorough examination was conducted, including a review of the literature, examination of field and herbarium specimens from both native and non-native species, microscopic analysis of leaf ultrastructure, chemical analysis of taxane content, and the construction of GIS models to predict the occurrence of the native species. In the review and examination of morphological features, it was found that the best features for separation of the taxa were plant height, the number of the rows of stomata per abaxial leaf band, and the location of papillose cells on the leaf epidermis. In particular, the SEM studies showed that stomatal bands are a reliable way of differentiating native and non-native Taxus species within Kentucky. A key to the taxa was prepared, as well as descriptions of the species. The chemical analysis failed to uncover any reliable differences between taxa utilizing only five taxanes. GIS models were prepared for 13 counties in eastern Kentucky, and these predicted the most likely occurrence of Taxus canadensis in each portion of the county. This study documented three species of Taxus that occur in Kentucky, T. baccata, T. canadensis, and T. cuspidata. Taxus canadensis is the only native species, considered to be a glacial relict, and is currently listed as a state threatened species. The other two species occur only rarely in nature as escapes from cultivation, likely from the spread of seeds by birds. There is no evidence of hybridization between native and non-native species. It was concluded that microhabitat requirements for T. canadensis are very restrictive, and that ongoing climate change may impact Kentucky's native population of T. canadensis.
"],"dc:format":["application/pdf"],"dc:identifier":["https://encompass.eku.edu/etd/302"],"dc:publisher":["Encompass Digital Archive, Eastern Kentucky University"],"dc:rights":["Copyright 2015 Robert Reed Pace"],"dc:source":["Encompass Digital Archive: Online Theses and Dissertations"],"dc:subject":["Ecology","Habitat Modeling","Kentucky","Taxanes","Taxus canadensis","Plant Biology"],"dc:title":["The Status of the Genus Taxus In Kentucky"],"dc:type":["Master Thesis"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_level":["Master's"],"thesis:degree_name":["Master of Science (MS)"],"thesis:institution_name":["Eastern Kentucky University"]},"updated_at":"2026-07-24T02:15:32Z"}