Brassia orchids have large, spider-shaped flowers, hence the other name Spider Orchids. They are not only extremely nice and beautiful but also they are true botanical curiosities – they are pollinated by female wasps of genera Pepsis and Campsomeris, who use spiders as feed container and vessels for their developing eggs and larvae. Confused wasps start fighting Brassia flowers as they are fighting actual spider, instead, they are just pollinating Brassia’s flowers. So, wasps believe that flowers of Brassia with elongated tepals, resembling spiders, are actual spiders. These marvelous orchids are natives to the area from Florida to northern parts of South America, they thrive in tropical rainforests.
Brassia Spider Orchids are close relatives of other Oncidinae orchids and belong to Oncidium Alliance. They are sympodial epiphyte or sometimes terrestrial orchids with profound pseudobulbs. Pseudobulbs are usually large, elliptic to oblong single or two-leaved pseudobulbs. Flowers are of whitish, greenish, yellowish and brownish shades, and all look similar to spiders – they have long sepals and petals, looking exactly like spider legs, and lip, which is not attached to a column, lip mimicking the shape of spider’s body. There are 29 currently recognized species in this genus and numerous hybrids, both natural and artificial. Brassia maculata or Spotted Spider Orchid is the type species; it has fragrant 5 to 8 inch wide yellowish spider-shaped flowers with brownish spots. Brassia verrucosa flowers are 6 inches wide greenish and fragrant with small brownish dots on both tepals and lips. Brassia signata has lovely 4 inch wide fragrant flowers with yellow-greenish spotted sepals and petals and white lips with brown mark. There is also quite unusual and rewarding Brassia King Kong ‘Uschi’ X Brassia Rex ‘Tahoma’ and Brassia Edvah Loo ‘Nishida’ with extremely large flowers.
Brassia orchids are quite easy to grow indoors. Given the fact that they are epiphytes, they require well draining potting mixture with medium bark, and you may also quite successfully grow them mounted on slabs (medium sized species, because they can grow very large), the best way is to pot them into hanging baskets to allow roots to be well aerated, because their roots are prone to rotting. Watering and fertilizers should be ample when a plant is actively growing, but let it dry between watering, overwatering is an actual danger to its roots. Light requirements are not very strict, they require bright filtered light with some direct sun in the morning, northern windowsills are not very good for them if it is not enough light and they will not bloom. Temperatures should be intermediate to warm and hot, they can thrive in common living rooms. Air can be dry, but humid air with strong air movement to avoid fungal diseases is excellent for Spider Orchids.