Paphiopedilum Michael Koopowitz is a primary hybrid of Paphiopedilum philippinense and Paphiopedilum sanderianum, the two species in the genus with the longest petals. P. philippinense var. roebelenii has impressively long twisted petals (see photo 1 in Six on Saturday #55), but P. sanderianum is in a class by itself–its petals can be up to one meter long. The petals of P. Michael Koopowitz are intermediate between the two species, never approaching the length of P. sanderianum but still long enough to impress. Various fanciful explanations for the long petals of these slipper orchid species have been devised (ladders for ground-dwelling insects?!), but the current hypothesis (if I correctly remember a paper I can no longer locate) is that they make the flower more visible to flying insects. Insect compound eyes aren’t great at making high resolution images, but they readily detect the motion of petals twisting and drifting on the slightest breeze.
P. philippinense var. roebelenii was described in 1883 and P. sanderianum in 1886, but their hybrid was not registered until 1993, despite it being an obvious cross to make. The reason for this century-long delay is that P. sanderianum was lost in cultivation and believed extinct in the wild for most of the 20th century. It was rediscovered in northern Sarawak in 1978, and plants started trickling into cultivation in the 1980s. When I started growing orchids in the mid 1990s, seedlings of P. sanderianum and its hybrids sold for eye watering prices–far out of the reach of my student budget–but near blooming-size seedlings can now be readily obtained for less than $100. That’s still expensive for a plant, but on par with other multifloral slipper orchids.
This seedling P. Michael Koopowitz has grown much faster and flowered earlier than a seedling P. sanderianum that I purchased at the same time (hybrid vigor, yeah!). The inflorescence has three flowers with 40-cm petals, which isn’t bad for a single-growth plant. If all goes well for the next few years, I can hope for inflorescences with four or five flowers, and perhaps longer petals, when the plant has a few more growths.