Lathyrus biflorus is a rare species of wild pea known by the common name twoflower pea. It is endemic to Humboldt County, California, where it is known only from the Mount Lassic Wilderness. It is a member of the serpentine soils flora. This is a petite perennial herb growing thin, tough, fuzzy stems with leaves each made up of two pairs of small linear leaflets. There are tiny bristlelike tendrils. The inflorescence bears two greenish-white pea flowers each up to a centimeter wide.