The medial petal, called the labellum or lip (6), which is always modified and enlarged, is actually the upper medial petal; however, as the flower develops, the inferior ovary (7) or the pedicel usually rotates 180°, so that the labellum arrives at the lower part of the flower, thus becoming suitable to form a platform for pollinators. This characteristic, called resupination, occurs primitively in the family and is considered apomorphic, a derived characteristic all Orchidaceae share. The torsion of the ovary is very evident from the longitudinal section shown (below right). Some orchids have secondarily lost this resupination, e.g. Epidendrum secundum.
If your Catasetum orchid leaves begin to yellow and drop off, do not despair; this deciduous orchid loses its leaves naturally during winter dormancy. There is much variation in appearance between Catasetum species, but one feature they all have in common is the trait of producing male or female flowers, which bear little resemblance to each other. The male flowers have an anatomical trigger that forcefully ejects pollen onto visiting bees.
Once you develop more than a passing interest in orchids, you will quickly notice how diverse this exotic plant family is. Encompassing genera that yield both the vanilla you love to bake with and fragrances you love to wear, each flower has unique characteristics and care requirements. Compare your plants to some of the most commonly cultivated orchids to help you determine what type of orchid you are growing.