Most of these plants go into a dormant period after flowering, when all growth stops. The plant will lose all foliage and should be kept mostly dry until growth resumes. These are Sinningia tubers. The popular mini-Sinningias are members of this group. This group of plants also has a type of underground storage mechanism.
Rhizomes form along the roots and are renewed each growing season.
Rhizomes have overlapping scales that resemble those of a pine cone. Most rhizomatous gesneriads have a dormant period, just like their tuberous relatives. Rhizomes can also form above the soil level. These are called propagules. This illustration shows a Kohleria rhizome.