Florets 3, the lower 2 sterile and glume-like, the upper one fertile. Lemma and palea green to yellowish, often dark red at apex, covered with stiff transparent hairs. Awn variable, stout, up to 11 cm long, often reddish. Anthers 6, 3.5-6 mm long , yellow or brown. Stigmas protruding, blackish-purple or brown.
Leaves usually turn brown as grains mature.
Rice fields, sites with shallow, standing or slow-running water. At publication time, no known populations of perennial wild red rice have ever been found in California. Previous populations of perennial wild red rice hybrids in the Sacramento Valley have been eradicated. Seeds fall near the parent plant or disperse to greater distances as rice seed contaminants, with human activities, water, soil movement, and possibly birds. Seeds do not survive ingestion by waterfowl.