The genus Hystrix was basically circumscribed as consisting of species that lacked glumes or had only vestigial glumes. It is always a risky business to base taxon delimitation on the absence of a character for absence can come about through many different paths. Hystrixappears to illustrate this risk. Its type species is Hystrix patula L., a North American species that has the genomic constitution StH. According to most people working in the Triticeae, such species belong in Elymus. If such a treatment is accepted, an appropriate generic name for the remaining species is need - unless they are placed in other genera.
The other North American species included in Hystrix, H. californica, has been shown to have a genomic constitution similar to that of species of Leymus. The same seems to be true of some other species. Some taxonomists, however, continue to recognize Hystrix as a genus. The following table is taken from Baden et al. (1997) treatment of the genus. It will serve as a useful page for keeping track of the species for which genomic data are, or are not, available.
M.E. Barkworth 2005
| Hystrix californica (Bol.) Kuntze | 56 (Myers 1947; Jensen & Wang 1997) | NsX | Jensen & Wang 1997 | |
| Hystrix coreana (Honda) Ohwi | 28 (Tsvelev 1983; Baden et al. 1997) | NsX | Ns present (Dubcovsky et al. 1997; Jensen & Wang 1998); 2/2 strong Ns bands; 1/3 Y bands, weak; 2 out of 3 weak St bands. (Svitashev et al. 1998) | |
| Hystrix duthiei (Stapf) Bor | ||||
| Hystrix duthiei (Stapf) Bor subsp. duthei | 28 (Baden et al. 1997) | NsY | 2/2 strong Ns bands; 1/3 Y bands, weak; no St band (Svitashev et al. 1998) | |
| Hystrix duthiei subsp. japonica (Hack.) Baden et al. | ||||
| Hystrix duthiei (Stapf) Bor subsp. longearistata (Hack.) Baden et al. | 28 (Osada 1989) | |||
| Hystrix komarovii (Roshev.) Ohwi | 28 (Tsvelev 1983; Baden et al. 1997) | NsY | 2/2 strong Ns bands; 1/3 Y bands, weak (Svitashev et al. 1998) | |
Hystrix patula L. TYPE SPECIES |
28 (Dewey 1982; Love 1984) | StH | (Dewey 1983); 1/3 St bands, strong; 1/2 Ns bands, weak (Svitashev et al 1998) | |
| Hystrix sibirica (Trautv.) Kuntze | 28 (Tzvelev 1983) | |||