Reader André Schuiteman, who works at the Royal Botanic Gardens at Kew, is part of a team that has discovered and described the world’s first night-blooming orchid. The species, Bulbophyllum nocturnum from New Guinea, is described (along with other species) in a new paper in The Botanical Journal of the Linnean Society (reference below). André wrote me:
I think the plants I study (mainly orchids from Southeast Asia) qualify for coolness, and I’m also a faithful, no, make that loyal, reader of your pseudoblog. Recently, I was involved in the description of the first night-flowering orchid known to science, which has generated quite a bit of publicity in recent days.
Now orchids are known that flower over long periods, including during the night. The famous Angraecum sesquipedale of Madagascar, also known as “Darwin’s orchid,” is pollinated at night by a moth. Readers may know the story of this species: it has an extraordinarily long nectar spur—27-43 cm (10.6-17 inches). Allow me a brief digression to describe it.
The spur contains nectar at the bottom, which attracts pollinators. But to pollinate the orchid, those pollinators must have a tongue long enough to extend the whole length of the spur, allowing the orchid’s pollen sacs (pollinia) to touch the pollinator’s head or body and be detached from the flower. Early biologists theorized that the complexity of this orchid required a divine creator (an early instance of ID!), but Darwin theorized in his orchid book that the long nectar spurs suggested an unknown pollinator with a long tongue. Here’s the flower:
And indeed, a pollinator, the moth Xanthopan morgani, was discovered in 1903. As Wikipedia notes: “The moth approaches the flower to ascertain by scent whether or not it is the correct orchid species. Then the moth backs up over a foot and unrolls its proboscis, then flies forward, inserting it into the orchid’s spur.”
The flower’s strong scent is produced only at night, and that is when the flower is pollinated. But the flowers last several days, blooming during the day as well. Here’s the moth, with that long proboscis unrolled:
The new orchid described by Schuiteman et al., however, blooms only at night, at least as judged from its behavior in the Leiden University greenhouses, where the flowers open at about 10 p.m. but wither and die by 10 the next morning (no blooming has been observed in the wild). Here’s the new night-bloomer:
Note the long appendages that dangle from the flower and move freely even in the slightest breeze; here’s a closeup:
Schuiteman et al. don’t know what these structures are for, but raise the intriguing possibility that they mimic the fruiting bodies of slime molds. The dangly bits of B. nocturnum, for example, look like the fruiting bodies of Stemonitis pallida:
It’s possible, though of course highly speculative, that these appendages attract flies that feed on slime mold fruiting bodies (there are old reports that the flowers of related species have a fungus-like smell), and deceive the flies into pollinating them. This idea isn’t too far-fetched, as of course lots of deceptive flower morphologies are known in orchids (some mimic bees, fooling the males into trying to copulate with the flowers as a way to get the flower pollinated).
André also sent me pictures of many other new species in the genus. He adds:
This species belongs to a group of generally rare and bizarre species known as the section Epicrianthes of the genus Bulbophyllum (the largest orchid genus, with about 2000 species). These are little known even to orchid specialists, so I thought you might be interested to show some of them on your website. I attach pictures of 8 species, 5 of which were only described during the last 6 years, and only one more than 30 years ago. In my opinion these orchids are fascinating and deserve to be better known.
Here are some of them.
This species, too, has dangly bits that look like fruiting slime molds. Here’s one fungus that B. cimicinum may be mimicking:
The weird shape of many of these flowers remains to be explained. Perhaps some of them mimic other species, or are devices to release scent.
Many thanks to André for corresponding with me and sending the photos.
Schuiteman, A., J. Jan Vermeulen, E. De Vogel and A. Vogel. 2011.Nocturne for an unknown pollinator: first-description of a night-flowering orchid (Bulbophyllum nocturnum). Botanical J. Linn. Soc. 167:344-350.