Eryngium mathiasiae is a species of flowering plant in the family Apiaceae known by the common name Mathias' eryngo, or Mathias' button celery.

The plant was named for American botanist Mildred Esther Mathias of California.

It is endemic to the Modoc Plateau of northeastern California, where it grows in the vernal pools of the local river drainages, and other wet areas such as ditches.

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