Tillandsia is a genus of around 650 species of evergreen, perennial flowering plants in the family Bromeliaceae, native to the forests, mountains and deserts of northern Mexico and south-eastern United States, Mesoamerica and the Caribbean to mid Argentina. Their leaves, more or less silvery in color, are covered with specialized cells (trichomes) capable of rapidly absorbing water that gathers on them. Sometimes they are also commonly known as airplants because of their natural propensity to cling wherever conditions permit: telephone wires, tree branches, barks, bare rocks, etc. Their light seeds and a silky parachute facilitate this spread. Most Tillandsia species are epiphytes – which translates to 'upon a plant'. Some are aerophytes, which have a minimal root system and grow on shifting desert soil. Due to their epiphytic way of life, these plants will not grow in soil but live on the branches of trees, in deserts and on other substrates that will not be saturated with water for very long.