Catasetum Orchid

The Catasetum orchid genus has unisexual flowers, either male or female (they look different); which type appears is controlled by the lighting. If grown in low lighting like a Phalaenopsis, male flowers will appear; if grown in high lighting like a Cattleya they'll have female flowers. The two flower types look different, so there will probably be one or the other that you're looking for for the particular species you're growing. (The male flowers are usually preferred, as they often have small, green, hooded female flowers.)
Catasetum macrocarpum
Ctsm. macrocarpum
Image courtesy of Alex Popovkin, Bahia, Brazil
Distributed under the Creative Commons Attribution 2.0 Generic license.
Like the unrelated Stanhopeinae, Catasetum and all its relatives in the Catasetinae subtribe (Cycnoches, Mormodes, etc.) are pollinated by male euglossine bees, which collect the flowers' fragrance, which they are thought to use in courting females.

The plants have large, thick pseudobulbs about a foot long or somewhat longer, with a fan of thin, veined leaves. Each year's pseudobulb will be bigger than the previous one if you're keeping the plant happy.

Flower stems emerge from the side of the pseudobulb above one of the leaves. One or two flower stems is most typical, with one to a couple dozen flowers each, depending on species.

They need a long dry rest after flowering to prevent rot; you'll know it's time for this when the leaves drop. During this time, water only the bare minimum needed to keep the pseudobulb from shriveling too much, such as every 3 weeks or so. But once new growth begins and roots are a couple inches long, you should be watering more normally, as the potting mix approaches dryness. Fertilize well during the active growing season, as the plant doesn't get a chance to be fertilized during its dry rest.

They like humidity of 50-70%. Also provide warm temperatures, 75-80°F (24-27C) during the day, dropping 10-15°F (6-8C) at night.

Repot just as new growth is beginning at the end of the dry rest. Sphagnum moss and fine fir bark work well as potting mixes for these epiphytes. Many growers like to divide these orchids at this time, usually leaving one pseudobulb from the previous season in each pot.

Return from Catasetum Orchid to Types of Orchids

Return from Catasetum Orchid to Orchid Care Tips Home