Hybrids betweenJuncus alpinus andJ. torreyi (Juncaceae) have been discovered in abandoned limestone quarries and on sandy beaches of Lake Erie in Erie and Ottawa counties, Ohio. The plants are morphologically intermediate in height, inflorescence length, number of glomerules per inflorescence, and number of flowers per glomerule. Both parents are diploid, 2n= 40; the hybrid is also diploid, 2n= 40, but at metaphase I both univalents and unequal bivalents are present. Using starch gel electrophoresis, ten enzymes were studied. The parents show differences in the allozymes of malic dehydrogenase, esterase, and malic enzyme. At each of these loci, the hybrids exhibit both the parental allozymes. Morphological and chromosomal data, augmented by the flavonoid and electrophoretic studies, confirm the hybrid nature of the newly discovered plants. The new taxon is described and namedJuncus xstuckeyi.