Soft fruits – gooseberry and blackberry – have barbs in abundance.
Invicta gooseberry produces large golden fruits and is worth growing, but when pruning to keep the centre open and free from mildew, watch those spines.
Cultivated brambles offer thornless types, such as the heavy cropping Loch Ness, or a traditional prickly customer, such as Fantasia. The fruits are huge, the plant rampant, and wearing armour is advisable.
Agave Americana is the mother of them all when it comes to inflicting a painful wound. I could never allow those long, needle-sharp spines to develop naturally. Some specimens in public places have either had them removed or corks placed on the end.
Facing such adversity in growing these otherwise useful perennials does have a positive angle. We could turn their defensive attributes to our advantage, such as plugging a gap in the hedge.
Such plants can play a part in the fight against crime; reference police pamphlets listing suitable plants to grow near vulnerable areas of the house.