I'm not sure what you're looking for in the way of a story line. You could look up the ethnobotanical uses of the native plants and talk about how the Indians and early settlers used them. A good easy-to-find source would be Plants of the Pacific Northwest Coast by Pojar and Mackinnon, from Lone Pine Publishing. It's the classic field guide for native plants that everyone carries into the field with them, so you should be able to find a copy easily. They have a Notes section on most every plant where they discuss ethnobotanical uses among other things.

This site from google mentions a few natives, not much story.

http://back2theland.blogspot.com/2009/07/fuzzy-purple-flowers-of-hardhack.html

And educational site below-

Here is a link that might be useful: twinberry

Indian planting lore.

Here is a link that might be useful: Fourth-Sister-Secrets

My memory fails me today, but there is a very nice story about the mouse that dove inside the Douglas Fir cone. It is a fairly common one that I have heard some kiddos retell to their friends. Also, if Bleeding Heart is native, there is a good story that involves moving parts of the flower to tell the story. I will try to connect with the young folks who told the stories - they are now in their twenties....and hope that they remember.

Definitely get the book by Pojar and Mackinnon. It's not expensive and it contains everything you'll need, including native plant legends.

I'd definitely include camas, Camasia quamash, in the garden. It's a beautiful plant with spikes of blue star-shaped flowers and the bulbs were a staple food of native peoples here.

there are some good quotes in the lewis and clark journals about camas. they absolutely hated the taste of the plant, but it was a critical part of their diet.

What about Mouse Tail Plant (Arisarum proboscideum)? It only fulfills one of your 3 requirements, but it is an easy care plant, pretty leaves and the flowers are delightful for children.

Our camas comes up every year, does not bloom.

Thanks. I've been reading the suggestions each day as the posts come in.

Blind camas planting likely needs more light or more fertility, same as with other bulbs.

Most likely more fertility. It takes a fairly rich soil to support the production of bulbs, if clumps not getting enough nutrition to size up blooming does not occur.

I also remember (vaguely) the story of the mouse that dove into the Doug Fir. My students absolutely loved it when they heard it at camp. Does anyone remember the exact story? I know that if you look at a cone, you see the mouse's tail...

Watch out. A mamma or pappa can screw you over. Everyone can.
PsuedomenzeeseeI. Latin is cool.