Iris douglasiana, Coleman Valley Road, Sonoma County, California
Iris douglasiana, Coleman Valley Road, Sonoma County, California
Range: Most extensive of all Californicae: coastal areas extending 700 miles between Santa Barbara, California and central Oregon.
Original material: Monterey region, coast of central California, by David Douglas 1830?
Key identifying features:
1. Stems often branched, each branch bearing 2-3 flowers
2. Ovary / seed capsule triangular in cross section, with a nipple-like projection at end near flower tube
3. Floral tube ¾ to 1 inch long
4. Leaves shiny green above, dull green below, ¼ to 1 inch wide
Flower color: Usually shades of light blue-violet to dark purple; occasionally white, rarely yellow.
Habitat: Grows naturally along coastal zones, usually within sight of the ocean; it is common on bluffs and treeless grassy hillsides. It sometimes extends farther inland in areas where human activity has opened forests to abundant sunlight. Unpalatable to livestock; some ranchers consider it an aggressive weed.
Douglas iris clumps are often single clones; they may
be hundreds of years old. (Mendocino CA, Colin Rigby)
Comment: This is a vigorous, highly successful iris, common and widespread in coastal areas. It readily crosses with each of the other PCNIs where their ranges overlap.
When Douglas iris is found farther inland, it is usually because it has crossed with other local iris species, better adapted to less exposed, shady habitats. If you know the local iris, you can often see evidence of this genetic mixing.
Some long established natural hybrid populations have been given their own names, like "Thompson's iris" along the California/Oregon border, and the "Marin iris" and "Santa Cruz iris" in the Coastal Range just north and south, respectively, of San Francisco's Golden Gate.
Iris douglasiana is widely used in the nursery trade, both as DOUGLAS IRIS, the species, and as a parent stock for many successful hybrids. In some way, it is involved in nearly all the named PCI horticultural varieties. Some are pure, wild plants cultivated because of certain unusual features. But most are man-made hybrids - the result of crosses from specially selected parents.
A few of the more successful strains made from pure species Douglas iris include "Amiguita" - blue bi-tone with a purple signal spot; "Canyon Snow" - all white; "Harland Hand" - purple, with a long blooming season; and "Mendocino Banner" - white with purple veins and contrasting purple style crests.