What is the difference between thorns …

Criteria

Spines

Thorns

Part of the plant

Spines are modified leaves or part of leaves

Thorns are modified branches

Location

They are placed at the same positions as leaves and have a bud in their axil

Thorns develop in the axil of the bud in place of leaves and thus can only be seen at the node of the plant

Connection to vascular tissue

May not be connected to the vascular tissue as they are not placed too deeply

Connected to the vascular tissue as they are placed deeply

Function

Protect the plant and prevent excess transpiration

They protect the plant and act as the climbing part of the plant

Formation

They are formed from external tissues and are exogenous

Thorns are formed from internal tissue and are called endogenous

Examples

Opuntia, Agave, Cactus

Carissa, Duranta