From the whole plant of Aerides crispum, a new phenanthropyran derivative was isolated. Its structure was elucidated as 2,7-dihydroxy-1,3-dimethoxy-9,10-dihydrophenanthropyran on the basis of spectroscopic data. This is the first report of phenanthropyran from A. crispum. (C) 1998 Elsevier Science Ltd. All rights reserved.