These plants are called Airplants, but their true name is Tillandsia. The reason why they are nicknamed "Airplants" is because they get the majority of their nutrients from the air around them. They don't have any roots and therefore don't need any soil. Airplants are epiphytes. An epiphyte is a plant that grows on another plant, like a tree branch or bark, but is not parasitic. They use their roots to anchor themselves rather than for nutrient uptake.
Mist them once every two weeks, preferably with rain or pond water. The muddier the water the better. Shake off any excess water and put them in a bright spot for at least 4 hours. This is key, as dampness is the main foe of an air plant. Their poor little cores will rot if they don’t get to drain and dry out! Your tillandsia should received bright, indirect sunlight or indoor lighting
Completely non-toxic to pets and humans.
Approx 10cm in diameter.
This arrangement has been made using several airplants in a cluster and has a metal hook to hang it.