Native Oregon purple flowers, August blooms

In my on-going quest to make my wedding as complicated as possible (and my blog as random), I'm looking into potted plants native to Oregon for centerpieces. Here's my attempt to track down purple flowers native to Oregon that bloom in August. They don't have these at Freddy's or Walgreen's, and at the nurseries I've visited, you're not gonna find someone who knows what's native, when something blooms, and what color it is. So again I turn to The Internet for my over-specific, long-tail demands.

It's possible some of these are not Oregon natives -- I haven't systematically double-checked my assumptions.

Downingia elegans
Elegant calicoflower
[Oregon Plant Atlas]
[USDA]
[Paul Slichter]
[Flickr]

Gentiana sceptrum
King's scepter gentian

photo by foliosus
[USDA]
[Flickr]

Pedicularis attolens
Elephant Heads

photo by molas
[Native Plant Society]
[Flickr]

Gentianopsis simplex
[Native Plant Society]
[Flickr]
[Flickr]
[Flickr]

Penstemon davidsonii var. menziesii

photo by msanseve
[Buy plant!]
[Portland Nursery]
[Washington Native Plant Society]
[Flickr]
[Flickr]
[Flickr]

Calochortus macrocarpus
Sagebrush mariposa lily

[photo by brewbooks]
[USDA]
[Flickr]
[Flickr]
[Flickr]

Lupinus macrophyllum
Lupine

photo by dleroy
[Portland Nursery]
[Wikipedia]
[Native Plant Society]
[Flickr]

Penstemon richardsonii
[USDA]
[Native Plant Society]
[Flickr]

Hoary aster

photo by delayedneutron
[Paul Slichter]

Rosy owl clover
[USDA]
[Paul Slichter]
[Flickr]

Larger Western Mountain Aster
[Paul Slichter]
[Flickr]

Collomia larsenii
Talus Collomia

photo by brewbooks
[USDA]
[Paul Slichter]

Eurybia radulina
Rough-leaf aster
[USDA]
[Wikipedia]
[Paul Slichter]
[Flickr]