1. low-growing annual herb of southwestern United States (Texas) having silky foliage and blue flowers; a leading cause of livestock poisoning in the southwestern United States • Syn: bluebonnet, buffalo clover, Lupinus subcarnosus • Hypernyms: lupine, lupin 2. closely resembles Lupinus subcarnosus; southwestern United States (Texas) • Syn: Lupinus texensis • Hypernyms: lupine, lupin