The plant genus Tillansia, a member of the Bromeliad family (Bromeliaceae), is found in the deserts, forests and mountains of Central and South America, and Mexico and the southern United States in North America. The thinner leafed varieties grow in rainy areas and the thick leafed varieties in areas more subject to drought. Moisture and nutrients are gathered from the air (dust, decaying leaves and insect matter) through structures on the leaves called trichomes. Tillandsia species are epiphytes, i.e. in nature they normally grow without soil, attached to other plants. Epiphytes are not parasitic, and depend on the host only for support. Common names for Tillandsia include air plant, ball moss (T. recurvata) and Spanish moss, the latter referring to T. usneoides in particular.