A New Combination in Phemeranthus (Montiaceae) and Notes on the Circumscription of Phemeranthus and Talinum (Talinaceae) from the Southwestern United States and Northern Mexico

Abstract. The name Talinum parvulum Rose & Standl. is transferred to Phemeranthus Raf. (Montiaceae) as P. parvulus (Rose & Standl.) D. J. Ferguson & T. M. Price. Described in 1911 from Durango, Mexico, this species closely resembles P. marginatus (Greene) Kiger [≡ T. marginatum Greene], which was described in 1912 from Nayarit. Phemeranthus marginatus is here treated as a taxonomic synonym of P. parvulus.