Prickle

A prickle is a small, pointed outgrowth on the surface of a plant, originating from the epidermis or outer cortical tissue. Unlike thorns, which are modified branches, and spines, which are modified leaves or leaf parts, prickles are not vascularized and do not represent a stem or leaf modification. This makes prickles a relatively simple epidermal protrusion rather than a specialized organ.

Prickles occur on a variety of plants, most commonly along the stems of roses and other members of the Rosaceae, as well as on canes of blackberry and raspberry. They can be short, curved, or hair-like and may be sparse or dense depending on species and growth conditions.

The principal function of prickles is protection against herbivores, serving as a physical deterrent rather than a refined defense system. In some climbing plants, prickles may also aid in anchorage by catching onto surrounding vegetation or substrate, helping plants perch or maneuver.

In botanical terminology, prickles are described as epidermal or cortical outgrowths rather than true organs. The term is descriptive and contrasts with thorns and spines; however, the lines between these structures can blur in some species, and gardeners often use "prickle" loosely to refer to any sharp protrusion.