Fasciation

Fasciation (also called “cresting”) on Foxglove (Digitalis).
Davis Sanders, ©2021, Clemson University
Fasciation (also called “cresting”) is a relatively rare plant growth condition that produces flattened, ribbon-like, crested, or contorted tissue in the stem, root, fruit, or flower head.
Fasciation can be caused by a mutation in the meristematic cells, bacterial infection, mite or insect attack, chemical or mechanical damage, or inherited as a trait. This phenomenon is documented in over one hundred different plant species, including cockscomb (Celosia), foxglove (Digitalis), cacti, and succulents.
Deformities are often localized to a single stem. Removal of the affected plant parts by pruning usually stops the abnormal growth unless the cause is a genetic mutation. Though fasciation is relatively uncommon, some plants may exhibit fasciation year after year because of a genetic predisposition.
Fasciated plants have the same cultural requirement as their standard (normal) counterparts.