Callusing
/ˈkæləsɪŋ/
Definition
Callusing describes the formation of a protective mass of undifferentiated plant cells over a wound or cut surface. It occurs after injury and during propagation, such as on stem or leaf cuttings before roots form. This tissue helps seal the damaged area, reduces water loss, and can be the starting point for new roots or shoots, but it is not itself a root, stem, or healed bark.
Biological Role
- Wound sealing: It helps exposed plant tissue dry and seal after a cut, reducing water loss and lowering the chance that fungi or bacteria enter the wound.
- Bridge to new roots: In stem propagation, this tissue often forms near the cut surface before adventitious roots develop. Adventitious means roots that arise from an unusual place, such as a stem.
- Condition-dependent response: Its development depends on living, active tissue and suitable warmth, moisture, and oxygen. If conditions are too wet, the cut surface is more likely to rot than mature properly.
- Useful cue for propagation: Growers watch for it on cuttings, graft unions, and divided succulent pieces because it suggests the plant has started repairing damage and may be ready for the next propagation step.
Related Terms
Cuttings
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Propagation
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Grafting
Grafting is a horticultural technique in which tissues from two plants are joined so they grow as one. The upper piece…
Layering
Layering is a vegetative propagation technique in which a stem forms roots while still attached to the parent plant…
Air layering
Air layering is a vegetative propagation technique in which roots are induced to form on a stem or branch while it…
Division
Division is a horticultural propagation technique in which a mature plant is split into two or more sections, each with…
Root
Root refers to the plant organ, usually below ground, that anchors the plant and absorbs water and dissolved minerals…
Cambium
Cambium is a thin layer of actively dividing cells in vascular plants, found between xylem and phloem in stems, roots…