Bulb scales: large 2-8; small 0-4. Stem 1-4.5 dm. Leaves 3-7, alternate, often ± crowded just above ground level, 5-19 cm; blade linear or oblong to narrowly ovate. Flowers nodding, odorless or sometimes with unpleasant odor; tepals dark brown to greenish purple or yellowish green, narrowly ovoid, 1.8-4 cm, apex not recurved; nectaries prominent, purplish to greenish, narrowly linear, forming narrow band 2/3 to equaling tepal length; style obviously branched for 1/2-2/3 its length, branches longer than 1.5 mm. Capsules angled.
This species is sometimes confused with Fritillaria agrestis, which grows in heavier soil and has flowers with an unpleasant odor. Fritillaria roderickii is still recognized by some botanists, but it appears to be little more than a localized flower-color variant of F. biflora var. biflora, and is valued by horticulturists for this reason.