[nwwildflowers.com] Limited Range, Identification Discussion: Erythranthe linearifolia is endemic to serpentine substrates in Shasta, Siskiyou, and Trinity counties; typical E. primuloides occurs in the same area but not on serpentine. Erythranthe linearifolia is distinct from E. primuloides especially in its narrow leaves and cespitose habit. A collection from Tulare County appears to be E. linearifolia (Shevock 10597, CAS), but this appears to be far out of range and the voucher should be reexamined; it probably is better identified as an unusual collection of E. primuloides. (link added by Mary Ann Machi)