Paphiopedilum lowii is generally considered to be one of the easiest of the multifloral tropical slipper orchids to grow and bloom, and it is frequently used in breeding to add bright colors and ease of culture to the resulting hybrids. Unlike some Paphiopedilum species which grow only on the slopes of a single mountain, P. lowii is native to penisular Malaysia, Sumatra, Java, Borneo, and Sulawesi. That wide range and the resulting genetic diversity may explain the color of my P. lowii plant.
This particular plant result from a cross of parents that were both heterozygous for ‘alba’ flowers–that is, they carried a recessive mutation that results in unpigmented flowers. The offspring of that cross have been widely distributed, and the expectation was that 75% would have normally colored flowers and 25% would have alba flowers. Instead, it seems that the flowers exhibit a range of color, from dark to quite pale, but no alba flowers have resulted. This is a fairly pale plant, and when I saw it on the nursery bench it almost glowed next to its darker siblings with chocolate pouches and lots of pigment in the dorsal sepal.
The lack of alba flowers in the cross suggests that the two parents carried mutations in two different genes. This occurs frequently when alba specimens of two different species are hybridized, but to occur in a cross of the same species suggests that the parents were genetically distinct–perhaps a consequence of the species’ wide range. The variation in depth of color might also be a consequence of crossing cultivated plants that originated from different wild populations. A commenter in this discussion points out that the color of P. lowii varies among different populations, with paler flowers coming from Sarawak.
But that’s enough geekery. Here’s one last photo to reinforce one of the best reasons to grow slipper orchids. The flowers that I photographed in early April, several weeks after they opened, are just starting to fade at the end of May.
And the flowers of the Paphiopedilum hirsutissimum that I photographed in March are still going strong.