I would add to Ron's useful categories another broad group, really a number of groups, that range from herbaceous (non-geophytic) to shrubby. Some are truly woody and others are succulent, or simply herbs. This is a sizable group, especially in tropical South America, and with a few exceptions they are very poorly known in cultivation. Some, like O. rusciformis, are especially interesting. This "group" suffers as much or more than the South African species from hardly any attention from botanists. Slogging through the older literature, when available, is not an easy way to name these plants or learn more about them. What we need is solid taxonomic revisionary work from brave and energetic students. Dylan