The Collaborative International Dictionary of English v.0.48:

Tillandsia \Til*land"si*a\, n. [NL., after Prof. Tillands, of
   Abo, in Finland.] (Bot.)
   An immense genus of epiphytic bromeliaceous plants confined
   to tropical and subtropical America. They usually bear a
   rosette of narrow overlapping basal leaves, which often hold
   a considerable quantity of water. The spicate or paniculate
   flowers have free perianth segments, and are often subtended
   by colored bracts. Also, a plant of this genus.

   Note: Tillandsia usneoides, called Spanish moss, long
         moss, black moss, and Florida moss, has a very
         slender pendulous branching stem, and forms great
         hanging tufts on the branches of trees in the
         Southeastern United States and south to Argentina. It
         is often used for stuffing mattresses
         [1913 Webster + Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Tillandsia
    n 1: large genus of epiphytic or terrestrial sparse-rooting
         tropical plants usually forming dense clumps or pendant
         masses [syn: Tillandsia, genus Tillandsia]