Abstract: Tillandsia belongs to the air, rootless plants. The leaf surface and anatomical structure of 4 Tillandsia species (T. xerographica, T. streptophylla, T. velutina, T. tricolor) were studied. Results showed that: (1) Leaf surface of all the 4 varieties were covered with foliar trichomes, and shapes, cover forms and densities of foliar trichomes in 4 species were different. (2) The leaf epidermal cells were different in morphology. There were two cell shapes, near quadrangle and near quadrangle with peripheral wall. Cell sizes were not the same. There were no stomata on the upper epidermis, while had stomata on the lower epidermis. (3) The leaf anatomical structure included cuticular layer, palisade tissue, water storage tissue, vascular bundle and cavity, and no differentiation of palisade tissue and spongy tissue existed in mesophyll cells. A large amount of water storage tissue was near the upper surface or the lower surface, and there were big and obvious cavities between different vascular bundles. (4) The special leaf structure was closely related to the adaptability of the air grown and the different origins.

Key words: air plant, leaf structure, air grown, adaptability