Plants described as subsp. klamathensis differ from others of the species in having floral tubes 11–20 mm instead of 6–10 mm, style crests somewhat longer and narrower, and flower color and markings more like those of Iris bracteata or I. innominata. The latter species has an even longer floral tube, 15–30 mm, which could be evidence of introgression. Hybrids are known to occur in the area common to both species, in Douglas County, Oregon.

Iris tenax hybridizes with I. bracteata, I. chrysophylla, I. douglasiana, I. hartwegii, I. innominata, I. macrosiphon, I. purdyi, and I. tenuissima.