Apparently naturalizing?? Found this living individual, as well as one that died. There are several mother trees nearby that were planted in the 1960s
Northern wildrice is commonly cultivated, along with cultivated rice, in the area of the Yolo Bypass Wildlife Area. It is also escaped in wet sites. Variety interior differs from the more wide spread variety palustris in having lower pistillate branches with 9–30 spikelets (versus 2-8); pistillate part of the inflorescence 10–40 cm or more wide (versus less than 10 - but in the Yolo Bypass area at this time the inflorescence were immature and not fully spreading), stems 1–3 m tall (versus 2 m or less), and blades 10–40 mm wide (versus 20 mm or less).
Flickr album and species diagnosis at https://www.flickr.com/photos/plant_diversity/sets/72157689667478105/
Escaped from cultivation and persisting as a weed along an irrigation canal in Yolo Bypass Wildlife Area, Yolo County, California, elev. ~15 ft.