| 1 | Tepals dark red |
| 1' | Tepals whitish, yellowish, or pinkish |
| 2 | Internodes distinctly different in length on the same twig, often tufts of subpersistent stipules at the leafy twig apices; lamina with cystoliths (beneath); fruits smooth |
| 2' | Internodes mostly similar in length on the same twig, without tufts of subpersistent stipules at the leafy twig apices; lamina without cystoliths; fruits tuberculate |
| 3 | Tepals glabrous or ciliolate; lamina with cystoliths (beneath); fruits smooth |
| 3' | Tepals with stiff hairs; lamina without cystoliths; fruits tuberculate |
