First report of Utah fragile fern (Cystopteris: Cystopteridaceae) from New Mexico, and new nomenclatural combinations in Cystopteris tenneseensis


  • Michael D. Windham Duke University
  • Kathleen M. Pryer Duke University



Two recently analyzed collections of Cystopteris from New Mexico represent the first records of Utah fragile fern for the state. Our morphological reexamination of this taxon reveals a single character (the thickness of lateral cell walls in rhizome and petiole base scales) that consistently distinguishes it from tetraploid Cystopteris tennesseensis. Therefore, we propose the new combination C. tennesseensis subsp. utahensis to accommodate these disjunct, tetraploid populations of the southwestern United States. A second new combination, C. tennesseensis subsp. laurentiana, is provided for morphologically similar hexaploids from the northeastern U.S. and southern Canada.


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How to Cite

Windham, M. D., & Pryer, K. M. (2022). First report of Utah fragile fern (Cystopteris: Cystopteridaceae) from New Mexico, and new nomenclatural combinations in Cystopteris tenneseensis. Journal of the Botanical Research Institute of Texas, 16(1), 1–7.