Submitted by: Jim Tanner
The three most common types of mutation are crests, monstrose growth and variegation. All of these are mutations of the cellular structure of the leaf or stem growth tip (apical meristem) of the plant. In normal plants the growth tip is a point, and the biochemistry of the plant forces one tip to be dominant or at least locally dominant. In crests the genetic mutation removes this dominance, and instead of a single growth tip the area of active cell growth degenerates into a line. For monstrose growth, the local dominance is lost, and every growth tip tries to grow as if it were the dominant point.
Cresting and monstrose growth is not unique to succulent plants. Crests are found in many genera of non-succulent plants, including conifers and many common garden plants.
Crests and monstrose plants are grown exactly as normal plants of the same species. Some have weak roots, and only grow well as grafts. However, others are robust growers, and do perfectly well on their own. Careful observation of the health of the plant, and comparison to healthy non-crested plants of the same species will quickly show whether grafting is necessary. Mutant plants tend to be more sensitive to poor growing conditions, getting sunburn quicker, and getting unsightly brown spots more easily than normal plants of the same species. This is one of the many reasons they are often grown as grafts.
Crests flower and produce seed, just as other plants do, but less often. Good strong growth is probably the best way to produce a flowering plant. Mutations are not generally transmitted by seed; however, seed from a mutant plant is much more likely to be a genetic mutant than that from a normal plant. The genetic mutation is more likely to be the same as the mother plant, but monstrose and variegated plants are also possible.
The most common method of propagation of these plants is vegetative. Cuttings of are often grafted to speed growth and to preserve special growth forms.