Flowering rush (Butomus umbellatus) is an invasive wetland perennial monocot that is native to eastern Europe that invaded north America in the early 1900’s. Flowering rush made its way to the Great Lakes in the mid-1950’s and has now invaded lake and wetland systems along the U.S. – Canadian border causing a host of issues related to water quality and water use. Within the current invaded range two cytotypes, a diploid and a triploid, have been documented which much of the current research and developed management strategies have been largely on the triploid. Research presented here is on the diploid cytotype which is considerably understudied compared to its triploid counterpart. One study was aimed at understanding the phenology and resource allocation of diploid flowering rush from three study sites: Mentor Marsh, OH; Tonawanda, NY; and Unity Island, NY. It was found that diploid flowering rush had the aboveground tissue peak in early to mid-summer with little resource investment. Once the aboveground tissue peaked, the generated carbohydrate content was then diverted to the rhizome and rhizome bud tissues for long-term storage as starch and vegetative reproduction which peaks right before wintertime. Along with sexual reproduction occurring in the flowers, diploid flowering rush produces rhizome buds, which act as vegetative propagules, on a scale almost twenty times higher than the triploid cytotype. With high reproductive output, diploid flowering rush presents itself as a threat for further spread in the U.S.
Alongside understanding the phenological patterns of diploid flowering rush, abiotic factor influences were analyzed using ecological niche modeling. This was done to model site specific abiotic effects as well as the potential for further spread within the U.S. Diploid flowering rush displayed plastic responses to its environment with each study site being affected by different abiotic variables from levels of soil organic carbon content to precipitation seasonality. From ecological niche modeling, diploid flowering rush was determined to have high suitability along the east coast of the U.S. Records from the U.S. Geological Survey Nonindigenous Aquatic Species database were used to determine that numerous populations of flowering rush occupy areas of high suitability based on the generated ecological niche models. Research done on diploid flowering rush suggests that management should be aimed to control the aboveground tissue using herbicide treatments. This management should be done early in the growing season for effective control, otherwise, flowering rush will be minimally affected by ill-timed management. However, further research should be done to optimize management strategies further for populations of diploid flowering rush.
Date of Degree
Master of Science (MS)
Program of Study
Science, Engineering and Technology
Gebhart, M. G. (2023). Life history, resource allocation, and phenology of Diploid Flowering Rush (Butomus umbellatus) collected from populations in Ohio and New York [Master’s thesis, Minnesota State University, Mankato]. Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. https://cornerstone.lib.mnsu.edu/etds/1334/