I read the following paper about non-domesticated wapato production. In the past conference (possibly the Indo-Pacific Prehistory Association in 2014?), I heard of an archaeobotanical report about this plant.
- Hoffmann, T., Lyons, N., Miller, D., Diaz, A., Homan, A., Huddlestan, S., Leon, R. 2016. Engineered feature used to enhance gardening at a 3800-year-old site on the Pacific Northwest Coast. Science Advances 2: e1601282.