Question sent by ALBA CERVERÓ (Valencia). ISABEL MATEU answers:
Air carnations belong to the botanic genus of Tillandsia from the family of Bromiliceae, to which the tropical pineapple also belongs, that covers up to 500 species adapted to live on other plants (epyphitism) used for their supporting. They get their nutrients through their leaves, although their requiriments are very few. They get water from rain or from atmospheric humidity by means of some structures (trichomes) which absorbe and retain water, and which give their whitened hue to their leaves. Mineral salts and organic compounds needed for them to live, are taken from small animals that fall on them or are brought by hte wind. This why they are known as air carnations.
Isabel Mateu. Director of the Botanical Garden of the University of Valencia.