Oxypetalum lividum , a new species of Asclepiadoideae (Apocynaceae) from Peru

Oxypetalum lividum (Apocynaceae, Asclepiadoideae), a new species from the Department of San Martin, Peru, is here described and illustrated. Oxypetalum lividum is similar to O. weberbaueri , but it differs by its sessile, 1 – 5-florous inflorescences, pedicels 0.7 – 3.5 mm long, and flowers 9 – 11 mm long, which are borne on short pedicels 0.7 – 3.5 mm long; whereas O. weberbaueri has pedunculate, 10 – 20-florous inflorescences, pedicels 5 – 7 mm long, and flowers ca. 20 mm long. The bluish-green leaves of O. lividum may also distinguish it from all other species of the genus.