| This dissertation consists of three chapters that detail a plant molecular systematics study undertaken in the Department of Botany Ph.D. program at Miami University.; Chapter 1, Introduction to the Eriocaulaceae Martinov, provides a brief introduction to the Eriocaulaceae, a monocot family of 11 genera and approximately 1,200 species that is distinguished by a characteristic compact raceme that resembles the capitulum common in the Sunflower family (Asteraceae). Although the Eriocaulaceae is considered a natural group, relationships among its members are not well understood, which is generally due to the circumscription of eriocaul taxa at all levels by a few small floral characters. Recent phylogenetic analyses of the family using morphological and anatomical characters have produced conflicting results and not allowed for any resolution of relationships within the family. To test proposed relationships within the family as well as further examine the morphological based phylogenies, a molecular systematics approach was selected.; Chapter 2, A review of potentially useful molecular markers for systematics studies in the Eriocaulaceae Martinov, evaluates nine molecular markers for their potential phylogenetic usefulness with the Eriocaulaceae. Three markers judged most appropriate for examining relationships within the family were identified, the trnL intron, trnL/F spacer, and ndhF gene of the chloroplast genome.; Chapter 3, Molecular systematics of the Eriocaulaceae Martinov, presents a phylogenetic study of the Eriocaulaceae based on both individual and combined datasets of the trnL intron, trnL/F spacer, and ndhF gene. The phylogenies generated were largely congruent with varying resolution between analyses. Overall, results supported the monophyly of the Eriocaulaceae and identified two major lineages within the family corresponding to Subfamilies Eriocauloideae and Paepalanthoideae. Several genera were strongly supported as monophyletic (Eriocaulon, Lachnocaulon, Leiothrix), while others were clearly not (Paepalanthus, Blastocaulon, Actinocephalus). With few exceptions, the generic relationships identified differed from those present in the morphological phylogenies. The molecular phylogenies provided a basis for preliminary examination of hypotheses on morphological character evolution, as well as identification of general evolutionary trends. |
