Tillandsia

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. 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 the epiphytic way of life of the plants the peculiarity arises that these bulbs do not lie in the ground, but hang in the air on branches. They are perennial herbaceous plants which exhibit a multitude of physiological and morphological differences making this genus an excellent example of diversity. Having native habitats that vary from being epiphytic and saxicolous, species have certain adaptations, such as root systems designed to anchor to other plants or substrates, and modified trichomes for water and nutrient intake. Some of the species, like the majority of bromeliaceae, grow as funnel bromelia, whose stem axis is compressed. The leaves are then close together in rosettes, thereby cover the lower areas of the leaves, so that a funnel for collecting water. Leaf rosettes, which is a common physical characteristic in Tillandsia species, function as a source of nutrients, water, and as a water and humus-gathering organ. Floral characteristics typically involve bright, vibrant colours, with either blooms or inflorescence being produced on a stalk. The colour varies between red, yellow, purple and pink, which helps attract pollinators. These colour variations can also occur on the air plants' foliage during its blooming season. The hermaphrodite flowers are threefold with double perianth. The three free sepals are symmetrical and pointed. The seeds have a 'parachute' similar to the dandelion. Common pollinators of this genera include moths, hummingbirds and, more recently recognized, bats. They have naturally been established in diverse environments such as equatorial tropical rain forests, high elevation Andes mountains, rock dwelling (saxicolous) regions, and Louisiana swamps, such as Spanish moss (T. usneoides), a species that grows atop tree limbs. But there are also species that live lithophytic, so on rocks (but also roofs and even telephone wires). The green species with their claim to a cool-humid climate live mostly more in the shade terrestrial or in the lower levels of the forests. In contrast, almost all gray species live in precipitation-poor areas with high humidity. They prefer the full sun and can therefore be found in the upper floors of the woods, on rocks or (rarely) on the ground. Many of the gray species are epiphytes. Some species are more or less xeromorphic. Tillandsias, like other bromeliads, can multiply through pollination and seed formation. Since Tillandsia are not self-fertile, the pollen must come from another plant of the same species. Tillandsie takes many years to flower. With the fruiting the life of the individual species has come to the end. There are still seeds formed, then the mother plant is destroyed.