Iris tenuissima purdyiformis in the middle Feather River Canyon

Photograhs By Eric Imbert

Shasta Iris' unusual race purdyiformis remains little known and seldom photographed since 1937, when Robert C. Foster first named it based on three dried museum specimens. How these plants in the Feather River Canyon fit into the much larger Iris tenuissima population is still unstudied. Some collectors have simply applied the name purdyiformis to any Shasta Iris specimen with bract-like leaves along its stem. Fortunately, photographs are becoming available.

Eric Imbert of the University of Montpellier in southern France studies color in Iris. In the spring of 2008, he traveled along State Highway 70 up the Feather Canyon to where the plants later named purdiformis were originally collected. He found these at Elephant Butte tunnel, just east of the Plumas–Butte county line. The site is about 5 miles downstream from Rogers Camp, where Foster's specimens were found 74 years earlier.

Imbert's photographs nicely complement two accounts of the subspecies purdyiformis in Lee Lenz's Revision of the Pacific Coast Iris (l958, page 70), and Hybridization and Speciation in the Pacific Coast Iris (1959, page 298). Lenz himself studied the plants in the same area.

A beautiful set of environmental photos of the Feather River Canyon – a designated National Scenic Byway – can be seen in Chris Austin's "Maven's Photoblog". Elephant Butte tunnel is next to one of the PG&E dam sites pictured toward the middle of the series.