The third in our comprehensive studies of all known cultivars of indoor and ornamental houseplants or interior plants. This edition covers the cultivars of the genera Alsobia, Beaucarnia, Cereus, Echeveria, Euphorbia, Ficus, Fittonia, Hoya, Justicia, Kalanchoe, Radermachera, Rohdea, Sanchezia, Scindapsus, Selaginella, and Strelitzia. Many rare clones are imaged, described, and given new cultivar names for the first time, establishing these names and whenever possible histories and origins. The volume contains much original research from our cultivar.org plant collections, numerous trips to visit other collections and nurseries, catalogs, reference books, academic articles, botanical databases, and consultation with more than 30 genera experts in the field. When we don't have a clear answer we share all the evidence for the reader to decide. As with previous volumes, this work is designed to be a benchmark, stabilizing and establish nomenclatrue, clarifying decriptions in great detail, and service a discussion point around while future research may develop.