Masdevallia bangii is one of the smallest Masdevallias. The plant shown is growing in a pot only 3-4 cm in diameter. The tiny flowers are only millimeters in size and the plant only a few cm tall. It is native to Ecuador, Peru and Bolivia. Actually, the plant is no longer classified as a Masdevallia, but as Triotosiphon bangii. This particular plant was awarded as a Masdevallia, however, and given a Certificate of Botanical Recognition by the American Orchid Society. It is supposed to be tolerant of a range of temperatures, but I have found it a bit finicky, dropping leaves when not happy. I keep it cool and moist.
