Nine new species in four genera of Neotropical Malpighiaceae are described and illustrated: Banisteriopsis rostrata W.R.Anderson (Brazil: Minas Gerais), Bunchosia andina W.R.Anderson (Colombia: Antioquia, Caldas, Nariño, Putomayo, Quindío, Tolima, Valle; Ecuador: Azuay, Napo, Pichincha, Tungurahua); Bunchosia parrae W.R.Anderson (Peru: Loreto, San Martín, Ucayali), Bunchosia phaeocarpa W.R.Anderson (Ecuador: Napo, Orellana, Pastaza, Sucumbíos; Peru: Loreto), Byrsonima anisophylla W.R.Anderson (Brazil: Bahia), Byrsonima cardenasii W.R.Anderson (Colombia: Antioquia, Nariño, Riseralda, Santander, Valle del Cauca), Byrsonima goiana W.R.Anderson (Brazil: Goiás), Byrsonima nana W.R.Anderson (Colombia: Meta) and Tetrapterys catarinensis W.R.Anderson (Brazil: Santa Catarina).

Six new species of the Neotropical genus Tetrapterys (Malpighiaceae) are described and illustrated: T. amazonica C.E.Anderson (Brazil, Colombia and Peru), T. andersonii C.E.Anderson (Mexico), T. callejasii W.R.Anderson (Colombia), T. molinae W.R.Anderson (Honduras), T. rzedowskii W.R.Anderson (Mexico) and T. steyermarkii W.R.Anderson (Colombia and Venezuela). All have 4(–6)-flowered umbels as the ultimate inflorescence units, glabrous yellow petals, and samaras with a small dorsal wing in addition to the four large lateral wings.