cactus - any spiny succulent plant of the family Cactaceae native chiefly to arid regions of the New World

genus Lophophora, Lophophora - two species of small cacti of northeastern Mexico and southwestern United States having rounded stems covered with jointed tubercles: mescal

magic mushroom, mescal button, sacred mushroom - the button-shaped top of the mescal cactus; a source of psilocybin