Cristate, monstrose and variegated
Cactus and Succulents ... 1/2

Introduction

On a plant the growing point is the area of new growth as it occurs, usually the tip (called apical or apex) of the stem/s where new leaves form. It is what you remove when you want a plant to branch and encourage side growth eg Tomatoes and fruit trees.
The growing point is a collection of cells that are still actively dividing, but have not yet differentiated to become leaf or flower cells, it is also called the meristem.

With a solitary or non-branching cactus or succulent, there is just the one apical growing point out of which new stem and spines (and sometimes flowers) appear as it grows, giving them there symmetrical shape. In multi branch cactus and succulents each branch is a growing point.

Cristate

In a cristate, or crested plant instead of the growing point being a single lateral apex, it is a (long) horizontal line at the apex consisting of many growing points in a symetrical line, forming patterns like a fan if straight, or a "brain" if wavy, or like a rooster comb.

Monstrose

In monstrose plants, the mutation occur takes place all over the plant, not just at the top or apex. Growth points originate all over the stem or branches causing very irregular growth. The resulting plant may bear little or no resemblance to its sister or brother in the same species of plant.

Most crested or monstrose cactus and succulents are not as "strong" as their "normal" counterpart, with increased sensitivity to cold, drought, and insect pests eg. mealy bug and scale insect - which can easily hide in the many folds and crevices, protected from sight and insecticide - and fungal disease. Plants may flower, but less abundantly or maybe with disfigured monstrose or crested flower. They may be sterile and not produce seed. If seed is produced it's monstrose characteristics may be carried in some of its new seed generation (a monstrose cereus is more likely to produce monstrose seedlings) along with other types of genetic mutations such as variegation, but inheritance among these plants is highly variable and cannot be guaranteed.

No one knows how to force this kind of growth, although many theories have been put forward - radiation, mechanical injury, chemical injury of the growing point, and chemicals like colchicine that interfere with cell division. Taking a cutting from a monstrose cactus it will continue to grow monstrose on it's own roots, as will a grafted cristate plant - in fact one cristate can produce many plants for the retail sale in a nursery.

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