تکمه (کالبدشناسی)
Sign in to saveright|250px|thumb|This view of the cactus Mammillaria marksiana shows its pattern of prominent tubercles, with the spines emanating from each tubercle's tip.
right|250px|thumb|This view of the cactus Mammillaria marksiana shows its pattern of prominent tubercles, with the spines emanating from each tubercle's tip.