Maxillaria densa Lindl.

Maxillaria densa, commonly called the crowded maxillaria, is an orchid species with a distribution ranging from Mexico south to Nicaragua. This orchid produces multiple phenanthrene compounds: the phenanthrenediol gymnopusin, as well as 2,5-dihydroxy-3,4-dimethoxyphenanthrene, 9,10-dihydro-2,5-dihydroxy-3,4-dimethoxyphenanthrene, 2,7-dihydroxy-3,4-dimethoxyphenanthrene (also called nudol), 9,10-dihydro-2,7-dihydroxy-3,4-dimethoxyphenanthrene, 2,5-dihydroxy-3,4,9-trimethoxyphenanthrene, and 2,7-dihydroxy-3,4,9-trimethoxyphenanthrene.