Hystrix was a formerly recognized genus of grass (family Poaceae).
The genus Hystrix was created in 1794 by Conrad Moench for the species described as Elymus hystrix by Carl Linnaeus in 1753.
[1] Moench considered that E. hystrix was sufficiently distinct to be placed in a separate genus as Hystrix patula; the genus was to be used for species without glumes or with long setaceous glumes.
Subsequently a number of other grass species were placed in this genus.
[2] Genomic studies from the 1960s onwards showed that H. patula does in fact belong in Elymus, as this is now defined.