In the Orchid Display House

Maybe it's the color -a true pink, without any of the red violet characteristic of so many 'pink' orchids -that makes Lycomormium fiskei so striking. And the size. Lycomormiums are hefty plants. Our plants, which are relatively small divisions of three or four pseudobulbs, measure three feet in height and must weigh 10 lbs each, basket included. The pendant inflorescence makes an open sided basket pretty much required for producing flowers on a Lycomormium.

Our lycomormiums have big waxy flowers and a strong sweet fragrance like many orchids pollinated by male Euglossine bees. They resemble the closely related Peristeria  -another genus with plicate leaves and smooth pseudobulbs -except for Lycomormium's immobile lip.

Lycomormium, Peristeria and Coeliopsis were for many years placed in the subtribe Stanhopeinae, but differ morphologically in having smooth ovoid pseudobulbs with 3-4 leaves, globose flowers, root hairs, a round viscidium adapted for attachment closer to the bee's head, a column foot, and the absence of a floral abscission layer allowing the flowers to fall off after they wither. Based on these morphological differences and on molecular analysis supporting the idea of two sister taxa, Whitten, Williams and Chase (2000) favor recognizing separate subtribes, Coeliopsidinae and Stanhopeinae.

Neomoorea irrorata

"Vinyl with citrus" is how Tres Fromme, our Landscape Design & Planning Manager, described the fragrance of Neomoorea irrorata yesterday. I happen to think Neomoorea irrorata has a sweet lemony jasmine scent. Name That Fragrance is a popular competitive sport around here. (...Okay, maybe there is a hint of new shower curtain scent in that fragrance.)

Neomoorea is one of our Euglossine bee pollinated orchids and is closely related to Houlletia and Stanhopea. Male Euglossine bees collect liquid fragrance from orchid flowers, not as food, but most likely to attract female bees.

I never wake up in a panic in the middle of the night thinking, The Neomoorea! Where did I put the Neomoorea? It's the size of a Smart Car and about as heavy. And it's not moving. So for the time being it's staying in the back up greenhouse. However you can admire one of its relatively small offspring flowering in the back of the Orchid Display House. A Neomoorea can grow frighteningly quickly given warmth, humidity and 50% shade.

Are there any other orchid species that share this particular shade of pumpkin orange? None leaps to mind. We have lots of gorgeous orchid species and hybrids in flower now during ORCHIDdaze: Surreal Beauty. I hope to see you here this weekend!

Openings: Coryanthes macrantha seedlings

Of course it's loads of fun to receive an orchid in flower. But even more fun is the exquisite anticipation that builds as you await the very first flowering of a newly matured plant. Will it resemble its parents? Will it be a surprising new color or shape? Or something intermediate? Do you ever envy plant breeders who experience this excitement for a living? Think about it. Many of them wait years to see their photosynthetic offspring's first flowers.

Flowering for the first time this month in our warm greenhouse are some seedlings of a fairly rare light colored form of Coryanthes macrantha, one of the Bucket Orchids.

Usually only a small percentage of the seedling offspring of an atypical form will resemble their parents. So I was expecting flowers with the typical bold red splashes. Surprise! Our first seedling has bred true. The petals and sepals are nearly white.

Of all the species of Coryanthes, Coryanthes macrantha is the most widely distributed. And throughout its range it exhibits some very striking color variation. Dr. Günter Gerlach's Coryanthes page on the Munich Botanical Garden's website has an outstanding catalog of Coryanthes descriptions and photos if you want to go crazy looking at the diversity in this remarkable genus. Dr. Gerlach notes that while the color and morphology of Coryanthes macrantha seedlings may vary throughout their range, the fragrances of all the clones that he examined are very similar. Coryanthes macrantha is pollinated by fragrance collecting Euglossine bees of the genus Eulaema.

Cycnoches warscewiczii, the Swan

Cycnoches warscewiczii ABG# 03-1121

Attention fans of Peristeria elata, the Dove Orchid. Allow me to introduce you to the Swan Orchid, which is flowering now in the Orchid Display House. Notice the graceful arching neck (the column), the white body (the lip) and chartreuse wings. Okay, it's an inverted swan, but never mind--it's lovely.

Cycnoches warscewiczii is just one of 30 or so species of Cycnoches, the Swan Orchids, which grow in the American tropics. Cycnoches produce flowers that are usually either male or female. In some species the male and female flowers look so strikingly different that they were initially thought to be different species.

The female flowers of Cycnoches warscewiczii

If you love orchid fragrances, you will want to experience this one. Like so many other Euglossine bee-pollinated orchids, this one smells delicious.

Acquiring pollen involves a sort of trapeze maneuver on the part of the bee. Even so, pollination isn't on his agenda at all. His goal is to simply to collect the liquid fragrance from the flower's lip, probably for pheromone production. As the bee grasps the margins of the lip with his two pairs of front legs, he releases his grasp with his two hind legs. His abdomen swings downward and touches the tip of the column, accidentally discharging the golden pollen masses onto his back.

The bee finishes collecting the fragrance and off he goes, cologned and resplendent, in search of yet more fragrance. Does he notice his cool new bling? Probably not. Eventually he arrives at a female flower, which he unwittingly pollinates while collecting fragrance.

Angraecum sesquipedale, The fragrant Star of Bethlehem Orchid

Angraecum sesquipedale flowering at the Fuqua Orchid Center

Angraecum sesquipedale

By far the most-asked question from nighttime visitors to the Orchid Display House is 'What smells so good in here?'

Winter is the season for night-fragrant Angraecoid orchids, two in particular. The first is Angraecum eburneum superbum, which starts flowering for us in November. The second is one of our most famous orchids, Angraecum sesquipedale, aka Darwin's Orchid, the Star of Bethlehem Orchid or the Comet Orchid, opening this week.

Angraecum sesquipedale is fascinating for lots of reasons, but today's post is just about its dreamy almost narcotic fragrance. The Darwin connection I'll take up in another post.

Angraecum sesquipedale is completely scentless during the day, and our daytime visitors just nod politely and walk away when told that it produces one of the best scents in the orchid family. But wait!

As darkness gathers the orchid releases a beguiling combination of scents--lily, Gardenia and Nicotiana. Interestingly, the scent changes as the flower matures. As Roman Kaiser writes in The Scent of Orchids, this description "applies to the fully developed flower on its 3rd or 4th night after blossoming. During the first two  nights, the scent is rather mixed, with a fairly marked indole note. This latter compound is found in the majority of night-scented flowers."

Night-fragrant flowers often produce scents reminiscent of jasmine, honeysuckle, tuberose, lilies and Gardenia. In the perfume trade, these scents are known as 'white-floral', and have been reproduced in a number of great perfumes.

Night-fragrant orchids that produce these scents are often white and are highly attractive to nocturnal moths and, apparently, people.

The effect on our nighttime visitors is remarkable. Many seem oblivious to the dazzling lights display as they veer off into the darkness in search of the source of the intoxicating scent.

More Mormodes

Mormodes oberlanderiana ABG# 05-1060 flowering at the Fuqua Orchid Center

A bee's eye view of the twisted column of Mormodes oberlanderiana. The shiny surface of the stigma is visible on the underside of the column.

From behind the flower you can see that the lip is twisted also.  The angle of  the lip and column creates  a characteristic placement of the pollinarium on the bee's thorax. When the bee enters a female flower the pollinia are in the correct position to be placed on the stigma.

The last of our four Mormodes species flowering this week is Mormodes oberlanderiana. I have to admit that I completely missed the subtle but gorgeous coloration of these flowers until I saw them in the morning light through my camera lens. What a beauty. Of the four species this one has, in my opinion, the most captivating fragrance.

Mormodes oberlanderiana is native to Colombia and northwest Venezuela where it grows as an epiphyte.

Peristeria

Peristeria (unidentified) species flowering in the Fuqua Orchid Center. Visible inside the flower are the broad yellow lip and the tip of the column.

If this orchid looks a bit familiar perhaps it reminds you of the Dove Orchid, Peristeria elata. The generic name, Peristeria, is derived from the Greek word 'peristerion' (dove) and refers to the dove shape that is formed by the fusion of the lip and the column.

The yellow almost-dove inside our Peristeria appears to be wingless because the lip lacks two large side lobes. In both species the lip is hinged and the weight of the pollinator (a Euglossine bee) landing on the lip causes the lip to rock. The bee is thrown against the end of the column--the dove's head--and in contact with the pollen masses.

What a terrific fragrance this orchid has! This Peristeria species smells like eucalyptus, but with a sweet floral aspect. The dominant chemical compound is eucalyptol (1, 8-cineole), a fragrance component of many Euglossine bee pollinated plants.

Anguloa clowesii

Anguloa clowesii flowering at the Atlanta Botanical Garden

I love that some of our Tulip Orchids are flowering indoors while our Horticulture staff is planting actual tulips outdoors.

Tulip Orchids are Andean in origin. Anguloa clowesii is native to Colombia and Venezuela where it grows at 1800 to 2800 m on the western slopes of the Andes. It was collected in 1842 by Jean Linden near the Nevado of Tolima, a Colombian volcano. Alvaro Arango M. writes in Orchids of Colombia, Vol. I, that in order to throw other collectors off the trail Linden reported it to be from the Sierra Nevado of Santa Marta, a coastal mountain range much farther north and not a part of the Andean mountain chain. This sort of deception was a fairly common practice among competing collectors. Linden named his discovery after one of the British financiers of his expedition, the Rev. J. C. Clowes of Manchester. Linden and his son later founded one of the most profitable 19th century orchid collecting firms.

Autumnal Anguloa

Some of our Tulip Orchids (Anguloa) are producing a late season flush of flowers.

I'm unsure of the identity of this lovely Anguloa which is unfortunately missing its label. The lip (barely visible in the photos) has characteristics that are intermediate between a couple of species. It may be a hybrid. For the moment it is a question mark, but still beautiful.

I love that the coloration is more vivid on the interior of the flower than on the exterior--clearly it's intended for the private enjoyment its pollinator. It's hard to look at this flower without wondering how the pollinator, a euglossine bee, experiences the colorful pattern and fragrance.

Openings: Stanhopea frymirei

Stanhopea frymirei captured in the early morning light immediately after watering. Photographing a Stanhopea can require a lot of patience. The tiniest adjustment in the plant's position sets the basket swinging like a pendulum for an eternity.

Stanhopeas are extraordinary orchids. The flowers are elaborate, enormous and intensely fragrant. The fragrances are complex mixtures of floral, culinary and resinous scents. They are delicious!

At first glance a Stanhopea flower can be baffling. But like all other orchids they have three petals and three sepals. The elongated part with two eyespots and two white horns is the lowermost petal, or lip. Reflexed backwards like enormous wings are two sepals. The third sepal arches forward, pointing toward the four-o'clock position. Over the top of that sepal are the two remaining petals which roll inward toward each other.

The reproductive part of the orchid flower, the column, is greenish-tinged in the picture above. Together with the lip, it forms a chute that channels a visiting bee toward the pollen. The yellow pollen masses can be seen in the second photo at the far end of the column, backlit and glowing yellow.

Openings: Coryanthes alborosea

Coryanthes alborosea red form flowering at the Atlanta Botanical Garden

This vibrantly spotted and spattered orchid is one of the siblings of the Coryanthes alborosea that I photographed last week. The seedlings, which are now flowering for the first time, are the result of a selfing of the red splashed color variant. A small percentage of the seedlings look like their parent.

This is a plant that leaves me awestruck. If you tried to describe it to a friend what would you say? Do you think anyone would believe you?

A Bucket Orchid Opens

Coryanthes alborosea opening at the Atlanta Botanical Garden.

Coryanthes alborosea one half hour after opening.

The right-hand flower of Coryanthes alborosea. Note the liquid already accumulating in the bucket.

If you arrive at the Fuqua Orchid Center greenhouses early in the morning you can sometimes catch a Bucket Orchid (Coryanthes) bud in the act of opening. The bud looks like an enormous wrinkled chrysalis. It usually takes a couple of hours to fully open. First, the bud splits lengthwise along its seam, then the petals and sepals reflex backward to reveal the amazing lip. Coryanthes flowers only last about three days.

Wednesday morning I photographed a pair of Coryanthes alborosea flowers as they opened. The half-opened sepals framed the lip like angel wings.

Love the furry cap.

Click here to find out how a Coryanthes flower works.

More Coryanthes in Flower

Coryanthes macrantha flowering at the Atlanta Botanical Garden

More of our extraordinary bucket orchids are flowering. Coryanthes macrantha (above) is one of the parents of the hybrid featured in my last post. You can see what the other parent looks like here. Although Coryanthes are, in my experience, among the more difficult orchids to grow, Coryanthes macrantha has always been a consistently strong grower for us.

I'm also looking forward to seeing the first flowers on the seedling offspring of Coryanthes macrantha var. alba this year.

Coryanthes, the Bucket Orchid

Coryanthes macrantha flowering at the Atlanta Botanical Garden. The genus Coryanthes is called the Bucket Orchid.

How it works. The  Coryanthes "bucket" (facing right) is part of the flower's lip, a highly modified petal. The other two petals and three sepals (left) are reflexed backwards like wings. Coryanthes flowers produce fragrance attractive to male Euglossine bees. After brushing the fragrance from the lip, the bee falls into the bucket.

The back door. After immersion in the liquid-filled bucket a bee must force his way out through a small opening at the rear where a pollen bundle is deposited on his back. 

Autumn brings a flush of new root and shoot growth to our (insert your own adjective) Bucket Orchids. A few, like Coryanthes macrantha, are far enough along in their development to produce flowers. The flower pictured above measures about four inches from top to bottom. A Coryanthes flower would make anyone stop for a second look.

Coryanthes, you make me crazy.

The fabulous but frustrating Bucket Orchid (Coryanthes)

Coryanthes are the most difficult plants I have ever grown. Clearly they are worth the effort--a fragrance that is almost edible, a grotesque (and let's face it, slightly pervy) appearance, a clever pollination mechanism, a symbiotic relation with two species of ants. But absolutely maddening in cultivation, at least in our greenhouses. The plants grow robustly for a year or so before I start to notice the subtle signs of decline: no new shoots appear, a few leaves are shed, and finally, the entire plant is leafless. If I remove the plant from its pot the root system is dead. Coryanthes make me want to bang my head against the wall.

Why? Coryanthes must be the orchid world's biggest mollusk magnets. While the adjacent pots of Phalaenopsis remain mollusk-free, it's rare to find a Coryanthes pot in any of our greenhouses that doesn't harbor at least a couple of slugs, and even worse, their minute evil cousins, the bush snails. Forget the metaldehyde, iron phosphate, beer, copper strips. It seems nothing kills these guys except the bottom of my shoe. And I have actually learned to enjoy crushing bush snails between my thumb and forefinger.

So, this summer I have applied a draconian solution--removing all the organic medium surrounding the roots and attaching our Coryanthes, young and old, to slatted cedar slabs as the new roots emerge. This is indeed a radical step since Coryanthes love moisture, plus it flies in the face of conventional wisdom which recommends mimicking an ant garden stuffed with acidic organic matter. But on these slabs the slugs & snails have nowhere to hide. And the mild but regular drying will make the Coryanthes a less appealing refuge for egg laying. That said, it's still a very humid greenhouse.

Look at those gorgeous root tips! Completely unmolested by slugs.

If the slabs look familiar to you it's because they are in fact simply the bottom of the classic cedar hanging basket sold by the major orchid supply houses. I think most people hang these slabs vertically, but I have decided to use them as rafts in order to retain a bit more moisture around the Coryanthes roots.

Time will tell whether or not this is a good cultural approach for Coryanthes.

Tulip Orchid Tuesday

Anguloa hohenlohii

All of the Tulip Orchids are lovely, but the russet colored Anguloa hohenlohii is especially beautiful. The inside of the flower is gold overlaid with red spots.

Anguloa clowesii

If you can tear your eyes away from the flowers you will see the new shoot visible behind the flowers. Those new shoots are practically begging for food. Tulip Orchids can become very large in bright light, coolish temperatures and with regular fertilizing during active growth. Some of the largest that I have seen were grown by Marc Hachadourian at the New York Botanical Garden-- beautiful plants with enormous pseudobulbs and leaves nearly two feet tall.

Many anguloas produce new shoots and flowers simultaneously, a trait that can exasperate a grower. (Shoots produced after flowering is a more common sequence in orchids.) By the time our plants have finished flowering and returned to the back up greenhouse the young shoots are nearly mature. I have to rush like crazy in order to repot them all before they finish their annual growth cycle. And I already have plenty to repot!

Tulip Orchids

Anguloa uniflora 

June is a terrific month to visit the Fuqua Orchid Center. Three outstanding orchid groups flower simultaneously: Laelia purpurata, Stanhopea and the Tulip Orchids (Anguloa).

This week you can see several Tulip Orchid species, including Anguloa virginalis and uniflora, pictured below growing side by side in the Tropical High Elevation House. In Peru these two species are often found growing together according to Henry Oakeley's book, Lycaste, Ida and Anguloa.

Both species grow as terrestrials or lithophytes in Andean tropics at about 1200 to 1500 m. Anguloa uniflora is endemic to Peru and it grows in extremely variable habitats--dry sunny slopes to moist dappled woodlands, writes Oakeley. Anguloa virginalis occurs over a wider geographical range Colombia, Venezuela, Ecuador, Peru and Bolivia often in full sun.

Cool and sunny is a big challenge in our greenhouses in summer. As our summers grow hotter more of our anguloas have begun to migrate permanently from the intermediate back up greenhouse to the Tropical High Elevation House.

Tulip Orchid fragrance will surprise you. It's Elmer's paste with a hint of menthol, an enticing aroma to male bees of certain species in the genus Eulaema. They collect the liquid fragrance by scratching the flower lip. The fragrance may be used to attract female Eulaema bees.

Anguloa uniflora in the Tropical High Elevation House

Anguloa is sometimes called the Cradle Orchid, in reference to movement of the lip, visible in the photo (above) edged with yellow. When a bee alights on the hinged lip his weight causes it to rock backward, pushing him up against the tip of the column and in contact with the pollen masses.  The bee often leaves the flower with the pollen attached to his thorax. It's easy to rock the "cradle" using your fingertip.

Anguloa virginalis in the Tropical High Elevation House

The journey of these two Tulip Orchids from the Andean rainforests to the 18th century Spanish court of Carlos III is a story with an Indiana Jones flavor. More about that in an upcoming post.

The Sweet Fragrance of Stanhopea

Stanhopea embreei in the Fuqua Orchid Center

The most deliciously fragrant orchids of summer are without question the stanhopeas. June marks the beginning of Stanhopea season in the Fuqua Orchid Center.

A Stanhopea in flower is an unforgettable experience. I remember years ago having to crawl under a greenhouse bench to get my first look at a pendant Stanhopea spike and to inhale its confectionery fragrance. Each flower looked like a bird in flight. And the fragrance was good enough to eat.

To my nose Stanhopea embreei smells like vanilla creme icing, even though my brain, which left Organic Chemistry by the roadside years ago, knows that the floral compounds common in Stanhopea include methyl cinnamate, benzlaldehyde, and cinneol.

Why the intense fragrance? Who is the intended recipient? Not us, of course. It's all about the pollinator: male Euglossine bees, who collect the fragrance, not for food, but to attract female bees.

Sad, but Stanhopea flowers only last about three days. It's as though the plant can't sustain the massive effort required to produce such an extraordinary creation. The good news is that a mature plant often produces several spikes each season. Come and enjoy the fragrance!

Embreea rodigasiana

Embreea rodigasiana flowering this week in the Fuqua Orchid Center

In the back up greenhouses at the Atlanta Botanical Garden is a bumper crop of seedling Embreea orchids that have just reached flowering size. They are making their debut this month in the Orchid Display House. Embreeas are considered to be rare and difficult in cultivation, so we are delighted to be able to show them to you.

Embreea is a striking orchid that resembles the closely related genus Stanhopea. It shares with Stanhopea the pollination syndrome associated with male Euglossine bees,--large tropical bees that collect fragrance. The waxy flowers are huge (about four inches) and their eucalyptus-like fragrance is highly attractive to Euglossines. The flower points downward and the column and lip together form a chute to guide the bee past the pollen masses located at the tip of the column.

Embreea produces a single-flowered spike, rather than the massive multiple flowered spike of Stanhopea. The horns on the lip have a very distinctive hatchet shape.

Since Embreea rodigasiana comes from an especially wet area of western Colombia--the Choco region--we water our plants more frequently than we do our stanhopeas. Embreeas absolutely need a humid greenhouse in order to flourish outside of the warm tropics. Our plants do well in a mixture of New Zealand sphagnum and chopped tree fern fiber. A wire or net basket is needed in order to accommodate the pendant spike which often grows downward through the medium.

Don't miss these! You can find them in the Orchid Display House this month in baskets hanging below the beams of the cedar pergola.