Iris beecheyana Herbert; I. douglasiana var. alpha Dykes; I. douglasiana var. altissima Purdy ex Jepson; I. douglasiana var. beecheyana (Herbert) Baker; I. douglasiana var. bracteata Herbert; I. douglasiana var. major Torrey; I. douglasiana var. mendocinensis Eastwood; I. douglasiana var. nuda Herbert; I. douglasiana var. oregonensis R. C. Foster; I. watsoniana Purdy Flowering Apr--Jun. Open woods, sunny slopes and fields; Calif., Oreg.
R. C. Foster (1937) named several varieties of Iris douglasiana, about which L. W. Lenz (1954) said, 'This is a widespread and extremely variable species whose total variability is being increased due to introgressive hybridization between it and other species with which it has come into contact. Well marked and distinct geographic races cannot be detected; however, pronounced variations are to be found within a single population. For these reasons no attempt is made here to segregate taxa within such a polymorphic species.' Iris douglasiana hybridizes with I. bracteata, I. chrysophylla, I. fernaldii, I. hartwegii, I. innominata, I. macrosiphon, I. munzii, I. purdyi, I. tenax, and I. tenuissima. The natural hybrid between I. douglasiana and I. innominata has been designated as Iris ×thompsonii R. C. Foster and the garden hybrid as Iris ×aureonympha E. H. English.