Paphiopedilum dayanum

That fringe of long silky hairs. Paphiopedilum dayanum always gets a second look from me. True, there are other Paphs with hairs, but this is the only one in our collection that triggers a grooming impulse. What other orchid has petals that need combing?

Paphiopedilum dayanum is one of those select plants that grows on Borneo's Mt. Kinabalu and nowhere else. Like many terrestrial orchids it occupies a specialized micro-habitat. Phillip Cribb reports that it grows in leaf litter under bamboo and at the base of trees on steep ridges around the mountain at 300 to 1450 meters elevation.

Why the the hairs on the petals? They may be an adaptation to attract flies that can pollinate the flowers. Hairs, warts, aphid-like bumps. Carrion colored flowers. Together, these comprise a syndrome associated with fly pollination.

Paphiopedilum dayanum has been trouble-free for us. It seems fine with temperatures on the warm side of intermediate (60 to 62º night minimum) in a shady greenhouse in a mixture of fine fir bark, chopped moss, charcoal and perlite.

All Hail Paphiopedilum rothschildianum

One of the most renowned orchids in cultivation is flowering now in the Orchid Display House. Meet Paphiopedilum rothschildianum, Rothschild's Slipper Orchid. Of all of the species of Asian Slipper orchids it is thought to be one of the rarest in nature.

You can't miss its regal presence among the other slipper orchids growing on our limestone outcrop. Our plant measures about 2' in diameter and has 5 flowering spikes.

Rothschild's Slipper Orchid, which Phillip Cribb in The Genus Paphiopedilum (1998) describes as 'arguably the most handsome in the genus' was one of the most sought after orchids at the height of the 19th century orchid mania. Its story of repeated tragedy has made it a poster child for conservation of orchid habitats. Harold Koopowitz tells the story in Orchids and Their Conservation (2001).

Paphiopedilum rothschildianum occurs only on Mt. Kinabalu* on the island of Borneo. It was collected and introduced into cultivation in Europe and Britain in 1887. The original site appears to have been deliberately falsified by the collector, Sander & Sons, who gave the location as New Guinea in order to mislead rival collectors. For the next fifty years the exact location of this extraordinary orchid was a matter of conjecture.

In the late 1950's two populations were discovered at the base of Mt. Kinabalu. In 1959 many of the plants in flower were collected to decorate a bower welcoming Prince Philip to Kota Kinabalu, according to Koopowitz. The sudden reappearance of this magnificent orchid would certainly have been noted by attentive orchid collectors worldwide. Some plants ended up in cultivation, and many of the rothschildianums in cultivation today are descended from these.

In 1979 a third population was discovered in an area of Kinabalu park which subsequently lost its protected status. Plants outside the park are threatened by shifting agriculture, logging, mining and commercial development. An attempt at propagation and reintroduction onto Kinabalu in the 1980's ended catastrophically when the reintroduction site was burned.

Cribb reports that only two of the three sites remain on Kinabalu. Plants inside the park, although they are protected, are not entirely safe from determined poachers. He notes that 'collectors could practically exterminate both populations in a relatively short time.'

Follow the link to find out more about the very strange and slightly macabre pollination mechanism of some slipper orchids, including Paphiopedilum rothschildianum.

*Mt. Kinbalu has a diverse flora that includes over 1200 species of orchids, an impressive figure compared with the fifty-something orchid species in our state.

Paphiopedilum wardii

Paphiopedilum wardii

Paphiopedilum wardii is a gorgeous olive green Asian Slipper Orchid native to Myanmar and southern China. I have always admired its coloration. But what's the story with the glistening bumps above the flower's pouch?

Several species of slipper orchids in the genera Paphiopedilum and Phragmipedium are visited by female hoverflies (Syrphidae). Female hoverflies select aphid colonies as brood sites for egg laying and their larvae eventually devour the aphids. John Atwood has observed hoverflies laying eggs on Paphiopedilum rothschildianum's staminode, which has raised glandular hairs. He concluded that the glandular hairs appear to the hoverflies to resemble the bodies of aphids. Atwood also observed the female hoverflies pollinating the orchid. This phenomenon--the attraction of female insects to false egg-laying sites in flowers --is called brood deception pollination.

Recently, Robert Pemberton has made several observations of hoverflies picking up pollina from Phragmipedium pearcei. Calaway Dodson also noted pollination of Phragmipedium longifolium by a hoverfly. Like most species of Phragmipedium, these two species have spots above the lip. It seems likely that the spots on Phragmipedium flowers attract hoverflies and facilitate brood deception pollination.

Is Paphiopedilum wardii pollinated by hoverflies? Is it pollinated through brood site deception? I don't know, but those glistening bumps would seem to suggest so.

Polka Dots Are Back

Paphiopedilum bellatulum in the Fuqua Orchid Center

Of course they are. The slipper orchids in the Fuqua Orchid Center were rocking the dots weeks before polka dots made a big splash at September Fashion Week in New York.

Scary spotted slippers in London. Photo by Mark Leibowitz

Paphiopedilum bellatulum (top) scores extra points with us for having gorgeous spotted flowers and leaves. We love the downy texture of the flowers and flower spike. It grows natively in the crevices of limestone outcrops in Myanmar, Thailand and southwest China. 

Autumn is a great time to see a cool-weather flush of flowers on the slipper orchids (with and without spots) in the Orchid Display House and the Tropical High Elevation House.

Mimicry & Slipper Orchids

Paphiopedilum glanduliferum, a tropical slipper orchid that grows on limestone cliffs  in New Guinea

I'm often asked if our slipper orchids are carnivorous. They are not. The pouch of the slipper orchid is instead involved in a fairly gruesome pollination mechanism.

Many tropical Asiatic slipper orchids are pollinated by flies. The spots, bumps, hairs, carrion colors and foul odors produced by the flower attract flies seeking a food source. 
Paphiopedilum glanduliferum is pollinated by hoverflies (Syrphidae) which normally lay their eggs on aphid colonies. Aphids are the food source for the larval hoverflies. The glandular hairs in the center of the flower may mimic an aphid colony.

Pollination takes place when the hoverfly becomes trapped in the pouch of the flower. The escape route forces the hoverfly in close contact with the pollen masses. As a result the fly often departs for another flower with the pollen attached to its body.

We don't have hoverflies in the Fuqua Orchid Center. Even if we did we would prefer to hand pollinate our orchids (using a pencil, very low tech) so that we know which plant contributed the pollen and on what date. A "controlled cross," in other words.

There are always Paphiopedilum orchids in flower in the Fuqua Orchid Center. We will be happy to point them out to you.

Our Kennel of Bulldog Paphs

"Bulldog" Paphiopedilum hybrids displayed on the Cube in the Orchid Atrium

Probably the most popular orchids on the hanging Cube in the Orchid Atrium are the Asian Slipper Orchids, the paphiopedilums, or "Paphs." These particular Paphiopedilum hybrids are colloquially known as "bulldog Paphs" on account of their broad-faced flowers and drooping petals. Among the most famous of the bulldogs is Paphiopedilum Winston Churchill. You can read more about this famous hybrid here.

The bulldog Paphs make outstanding display orchids. Their enormous shiny flowers are mesmerizing when viewed at eye level and they are extraordinarily long lasting (for Paphs, anyway)--eight weeks if you can keep the daytime temperatures at or below 72º.

Paphiopedilum species in nature are usually, but not always, terrestrial. They often grow as understory plants, or wedged into crevices in rocky limestone or granite outcrops. Adapted to an environment where there is a fairly dependable reservoir of moisture surrounding their roots, Paphs are not as drought tolerant as their epiphytic relatives, like Cattleya and Laelia, which often possess thickened leaves to resist moisture loss and pseudobulbs to store water.

Thus, in cultivation, Paphiopedilum orchids enjoy more subdued light, a more moisture retentive medium, and more frequent watering than Cattleya orchids.  They do well under lights or on an east facing windowsill. On a windowsill they will need a few hours of mild morning sun in order to flower. Most growers pot their Paphs in a mixture of fine grade bark, charcoal and perlite, often with some additional peat or milled sphagnum.

You won't want to miss these extraordinary orchids. And don't forget your camera!

The Garden is now open every night until 7 pm. The Orchid Daze display runs through April 15.