The stigma is rounded, truncate or bilobed and often edged with small teeth, it is the only species of Iris ser.

[3] While once common, disturbance caused by logging and opening up new highways has allowed other species to move in, in particular I. douglasiana and I. macrosiphon, and the resulting hybrids are abundant.

[3] The iris is found in Humboldt, Mendocino, Sonoma and Trinity counties in California,[3] and in southern Oregon.

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

[4] The cross with I. tenax, called "Iota", was made by the Englishman William Dykes, and was the first Californian Iris to win a Royal Horticultural Society Award of Merit, in 1914.