Plumas Iris (Iris hartwegii pinetorum) - Sierra Iris' double-flowered race

Photographs By Ron Parsons & Steve Ayala

Plumas Iris, a unique race of Sierra Iris, lives in a small area of Plumas County at the very northern edge of the species' range. In some years it seems to carpet open areas around Lake Almanor and Greenville (3,500-5,000 feet elevation), especially where the yellow pine forest has been recently logged, thinned or burned over. Setting it apart from the other Sierra irises and from Pacifica irises in general, the little Plumas Iris often opens its two white or yellow-cream flowers at the same time.

Alice Eastwood first described it as Iris pinetorum in 1931. It may be that it began as a hybrid of the Sierra iris and Shasta iris. Plants of both parent stocks live in nearby locations, and similar-looking hartwegii-tenuissima hybrids occur a short distance to the south in the Butterfly Valley Botanical Area near Quincy.

The floral tube of Plumas Iris is short and stocky - like other Sierra Irises, but slight longer (½ to ¾ inches) and thinner at the base, and its widely diverging spaths leave the ovary clearly visible. The Shasta iris side of its background is suggested by the often slender floral parts, wavy-edged sepals and petals (though some Sierra Irises also have this condition), and the long styles and especially style crests. Click on Ron Parsons' name above to see the album with all 12 of his Plumas iris photos.

Tuolumne iris, I. hartwegii columbiana by Ron Parsons

Plumas iris - Irus hartwegii pinetorum, Plumas County, California. Photos 1,2,4 - near Greenville. Ron Parsons, June 18, 2011.   Photo 3 - Old Haun Road near Canyon Dam, Lake Almanor. Steve Ayala, June 14, 2004.