The list of indoor bonsai trees and shrubs is huge, potentaly larger than the list of outdoor bonsai (as many have yet to be tried). The list of plants I have attempted to bonsai and recommend are include Dracaena 'compacta', Buddleja indica, Polyscias fruiticosa, Scheffera arboricola, Begonia sp, Coffea robusta, Citrus spp, Tamarindus indica, Dizygotheca castor, Cycas spp, Zamia spp, Crassula ovata, Portulacaria afra, and of course, the ficus.
What makes a bonsai indoorable are these guidlines, which mostly apply to all bonsai. The most obvious one being the plant must be woody. The plant also needs to have small or easily reduced leafs, and should branch well whem pruned (but not always). It should also have a long lifespan. Then there are the rules that strictly apply to indoor bonsai. They need to be able to tolerate indoor air and a lack of light, and be able to survive with no dormancy period. Any plant suiting these guidlines is a candidate for an indoor bonsai.
הדמיון הוא יותר חשוב מאשר ידע