In
botany, a
tendril is a specialized
stem,
leaf or
petiole with a threadlike shape that is used by
climbing plants for support, attachment and cellular invasion by parasitic plants, generally by twining around suitable hosts. They do not have a lamina or blade, but they can
photosynthesize. They can be formed from modified shoots, modified leaves, or auxiliary branches and are sensitive to airborne chemicals, often determining the direction of growth, as in species of
Cuscuta.