Lymanbensonia choquequiraensis, a new species from Cusco, Peru, is described and illustrated. This species is only known from the vicinity of the archaeological site of Choquequirao. L. choquequiraensis is compared to L. micrantha and L. crenata. The stems resemble L. micrantha (the geographically closest species from Puno, Peru) but differ in having four angled stems rather than two or three ribs. The flowers of L. choquequiraensis are much smaller than L. micrantha, of equivalent size to L. crenata but with significant morphological differences. This new species increases the number of Lymanbensonia species currently known to five.

Three species that were originally described under the genus Talinum Adanson (family Talinaceae), are here re-assigned and combined under the genus Phemeranthus Rafinesque (family Montiaceae) to bring them into accordance with related species, and to associate them with the proper family. Sectional categories are also established under the genus Phemeranthus.

Additionally two previously unnamed species are here described. Phemeranthus rhizomatus D.J. Ferguson from New Mexico, USA, and Talinum sonorae D.J. Ferguson from the southwestern USA & western Mexico.