Quillwort in the Quarry
Quillwort, (family Isoetaceae), family of about 250 species of seedless vascular plants of the order Isoetales. Quillworts are the only extant members of the order and are usually placed in a single genus, Isoetes (also spelled Isoëtes). The plants are aquatic or semi-aquatic, and most are native to swampy, cooler parts of North America and Eurasia. See also lycophyte and lower vascular plant.