Tubercle

For the lip feature, see Cupid's bow.
This view of the cactus Mammillaria marksiana shows its pattern of prominent tubercles, with the spines emanating from each tubercle's tip.

In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal.