Taxonomy and phylogeny of the flowering plant genus Diervilla (Diervillaceae)

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Hannah Elise Meeler (Creator)
Western Carolina University (WCU )
Web Site:
Katherine Mathews

Abstract: My research consists of a taxonomic and phylogenetic analysis of the genus Diervilla (Bush honeysuckle), containing three eastern North American species, Diervilla lonicera, Diervilla rivularis, and Diervilla sessilifolia (Diervillaceae). Because there is a large amount of morphological variation found within each species, taxonomic boundaries are unclear. Diervilla lonicera has the largest coarse geographic range, which spans from the southern Appalachians to northeastern Canada. Diervilla sessilifolia and Diervilla rivularis are endemic to a few states in the southern Appalachians. My research has three main components: 1) a study of morphological variation and historical range information using herbarium specimens; 2) a multivariate ecological field study of all three species in the locations where their coarse ranges overlap in the southeastern United States; and 3) a phylogenetic analysis of multiple populations of the three species and their outgroup, Weigela. There was no evidence of the three taxa growing together across their range. The multivariate analysis results suggest that morphological data can be helpful to separate the taxa, but only on a small geographic scale. The environmental data from the ecological field study were inconclusive, with locality being the strongest factor. The phylogenetic analysis showed that the three taxa share a few derived genetic mutations, but overall, there is very little sequence variation. Based on my analyses, I cannot conclude that D. lonicera, D. sessilifolia, and D. rivularis are indeed three distinct taxa.

Additional Information

Language: English
Date: 2018
Honeysuckles -- Habitat -- Appalachian Region, Southern
Honeysuckles -- Appalachian Region, Southern -- Morphology
Honeysuckles -- Appalachian Region, Southern -- Classification
Honeysuckles -- Cladistic analysis -- Appalachian Region, Southern

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