They have a special adaptation to climatic requirements of a six months dry season; examples are: Cattleya skinneri; Encyclia cordigera, Epidendrum stamfordianum, Vanda teres; Oncidium teres; Onc. cavendishianum, Onc. carthaginense, Brassavola nodosa. Keep them humid and they rot; for full list refer to OD77-179+