īˈsōəˌtēz noun
Etymology: New Latin, from Latin, houseleek, from Greek, from neuter of isoetēs equal in years, from is- + etos year — more at wether
1. capitalized : a large widely distributed genus (coextensive with the family Isoetaceae) of fern allies comprising the aquatic or marsh-growing quillworts that have a short buried lobed stem from which arises a tuft of quilt-shaped leaves bearing sporangia in their axils — see isoetales
2. plural isoetes : any plant of the genus Isoetes : quillwort 1