Editing Corm (section)

== Cormels ==
Corms can form many small cormlets called '''cormels''', from the basal areas of the new growing corms, especially when the main growing point is damaged. These propagate corm-forming plants. A number of species replace corms every year by growing a new corm. This process starts after the shoot develops fully expanded leaves. The new corm forms at the shoot base just above the old corm. As the new corm grows, short [[stolon]]s appear that end with the newly growing small cormels. As the plants grow and flower, they use up the old corm, which shrivels away. The new corm that replaces the old corm grows in size, especially after flowering ends.

The old corm produces the greatest number of cormels when close to the soil surface. Small cormels normally take one or two more years of growth before they are large enough to flower.

Cormels do have a reproductive function, but in the wild they also are important as a survival strategy. In most places where [[Storage organ|geophytes]] are common, so are animals that feed on them, whether from above like pigs, or from below like bulb weevils, [[blesmol|mole rats]], or [[pocket gopher]]s. Such animals eat through protective tunics, but they generally miss several cormels that remain in the soil to replace the consumed plant. Plants such as ''[[Homeria]]'', ''Watsonia'' and ''Gladiolus'', genera that are vulnerable to such animals, are probably the ones that produce cormels in the greatest numbers and most widely distributed over the plant. ''Homeria'' species produce bunches of cormels on underground stem nodes, and ''[[Watsonia meriana]]'' for example actually produces cormels profusely from under
[[bract]]s on the [[inflorescence]]s.<ref name= "MaNNing">{{cite book | last = Manning | first = John | title = Field Guide to Fynbos | publisher = [[Struik Publishers]] | location = Cape Town | year = 2008 | isbn = 978-1-77007-265-7 }}</ref>

Those growing from the bottom of the corm are normal fibrous roots formed as the shoots grow, and are produced from the basal area at the bottom of the corm. The second type are thicker layered roots called [[contractile root]]s that form as the new corms are growing. They pull the corm deeper into the soil. In some species contractile roots are produced in response to fluctuating soil temperatures and light levels. In such species, once the corm is deep enough within the soil where the temperature is more uniform and there is no light, the contractile roots no longer grow and the corm is no longer pulled deeper into the soil. In some other species, contractile roots seem to be a defence against digging animals and can bury the corm surprisingly deeply over the years. ''[[Wurmbea|Wurmbea marginata]]''<ref name="MaNNing" /> is one example of a small plant that can be challenging to dig unharmed out of a hard, clayey, hillside.