Bullish on Stanhopeas

Stanhopea hernandezii

For a long time I thought of Stanhopea hernandezii as a sort of junior sized version of Stanhopea tigrina, that mastodon of the stanhopeas. Both give the impression of a massive cranium and formidable tusks. But it wasn't until this summer when we flowered both species simultaneously that I was able to compare them side by side.

Stanhopea tigrina

In profile, it's easy to see that the the bottom of the hypochile is rounded like a bowl in hernandezii, but flattened in tigrina.

Stanhopea tigrina, a second color form

Stanhopea hernandezii, dorsal view

The horns are round in cross section and slender in hernandezii, but flattened and broad near the base in tigrina.

Stanhopea tigrina, dorsal view

Stanhopea tigrina, dorsal view

Stanhopea hernandezii, lip and column

Notice the striking difference in the columns of the two species: hernandezii's narrow column compared with tigrina's broadly winged column.

Stanhopea tigrina, lip and column

Stanhopea tigrina, lip and column

Stanhopea hernandezii, lip

With the column removed you can see how much broader the epichile is in tigrina than in hernandezii.

Stanhopea tigrina, lip

Stanhopea tigrina, lip

Stanhopea hernandezii, lip in ventral view

Stanhopea tigrina, lip in ventral view

Stanhopea tigrina, lip in ventral view

Stanhopea hernandezii, column

Stanhopea tigrina, column

Stanhopea tigrina, column

Stanhopea hernandezii and tigrina are both endemic to Mexico. S. hernandezii occurs on the southwestern slopes of the Mexican plateau at about 1,600 to 2,000 meters elevation in the states of Morelos, Mexico and Michoacan. I can't find referennce to a specific pollinator for hernandezii. The largest fragrance components measured by Gerlach (in Lankesteriana 2010) are cinnamyl acetate (64%) and benzyl acetate (11%).

Stanhopea tigrina is known from  the eastern slopes of the plateau at about 1200 to 1800 meters in the states of Tamaulipas, Hidalgo, Puebla and Vera Cruz. Its pollinator is Euglossa viridissima. The chocolate fragrance described so often in the literature (but which I cannot discern in our plants) derives from the combination of phenylethyl-acetate, a primary component of the fragrance, and vanilline, one of the secondary components, according to Rudolf Jenny.

Our S. hernandezii, which we received from a commercial nursery as S. ecornuta, flowered in August and probably won't be on display again until next summer. On the other hand, we have quite a few S. tigrina in our collection. The flowers only last about three days, but it's definitely worth stopping by to try to catch them when they flower in August and September. They are magnificent.

Stanhopea connata

Stanhopea connata ABG# 1993-2450

Not every Stanhopea smells like a pastry shop. Poor Stanhopea connata. It's the one Stanhopea that can clear a room.

Dorsal view of Stanhopea connata ABG# 1993-2450

While most stanhopeas have fragrances delectable enough to eat, Stanhopea connata exudes cresole and indole. Cresole is the fragrance compound associated with coal tar (think freshly poured asphalt). And indole has a fragrance described in botanical literature as fecal. I was not, to be honest, in a hurry to have a closed door photo session with Stanhopea connata.

Front view of Stanhopea connata

And that's too bad! Look at that face, with the bold tiger stripes and spots. I was completely charmed. Charmed and overwhelmed, actually.

Dorsal view of the lip and column with sepals and lateral petals removed 

Of course, it doesn't matter one bit what I think of the fragrance. The fragrance is all about attracting a pollinator. And it's kind of cool to think that there are fragrance-collecting bee species in the tropics who are mad for asphalt and cow dung.

Dorsal view of the lip without the column

My photo shoot with S. connata lasted about an hour. Over time, the cresole seemed to diminish and the indole began to assert itself. But by the end I hardly noticed. What a handsome plant this is. The images will be stored in ABG's image library.

Ventral view of the lip

Stanhopea connata grows as an epiphyte along the eastern cordillera in Peru, Colombia and Ecuador. It is pollinated by Eulaema speciosa.

Ventral view of the column

Deconstructing ruckeri

Side view of Stanhopea ruckeri 'Tikal' ABG# 1997-0230

A Stanhopea flower is an exquisite thing, but trying to observe one from every angle while it's still on the inflorescence is a frustrating experience because of the compact arrangement of flowers. It's especially hard to get a direct look at the upper surface of the lip because the column blocks its view. The best way to look at Stanhopea flower is to remove it and take it apart.

Dorsal view of Stanhopea ruckeri 'Tikal' ABG# 1997-0230

Dorsal view of the column and lip without the two lateral petals and three sepals

Dorsal view of the lip without the column

Ventral view of the lip

Ventral view of the column

Dissecting these flowers increases my admiration for them. And the powerful fragrance that is released inside our small closed library is wonderful. Some of them (like Stanhopea embreei, 99% trans-methylcinnamate) I want to inhale over and over again. How exactly do the Euglossine bees experience this fragrance, I wonder?

Two Stanhopea ruckeri Clones

Stanhopea ruckeri flowers in August and September in our greenhouses. It has been fascinating to observe the different color forms and scent variations among our plants. S. ruckeri varies in color from albino to apricot, and may occur with or without eyespots and scattered dots. Some clones have a scent that is almost undetectable. Others have a light floral fragrance. Still others smell like candy Red Hots. The morphology of their flowers is pretty similar. The biggest obvious difference is their scent chemistry.

The first two pictures show ABG# 1990-1503, a clone with lots of spots on the petals and sepals and two barely visible eyespots on the dorsal side of the hypochile. It has a light rosy floral fragrance whose main component is phenyl-ethylalcohol.

On the underside of # 1990-1503's lip are two more faint eyespots.

Another plant, # 1997-0230, has two bold eyespots. This clone smells like cinnamon (it's a mixture of trans-cinnamaldehyde, cinnamyl-alcohol and cinnamyl-acetate) and benzylaldehyde.

This plant also has a second pair of pale eyespots on the underside of the lip.

The extra sprinkling of tiny spots on the underside of the column were a surprise. The spots and the fragrances remind me that pollinators experience a sensory world very different from ours.

Stanhopea ruckeri, with its different chemotypes, is a puzzling entity. Calaway Dodson suggested that S. ruckeri may be a group of natural hybrids between S. wardii and S. oculata, but more research is needed.

We grow our plants in a mixture of long-fibered premium sphagnum and coarse chopped tree fern fiber. Stanhopea ruckeri is easy to grow in an intermediate (58º night minimum) temperature greenhouse and 60% shade. It grows quickly, produces multiple spikes and makes a handsome overwhelmingly fragrant specimen basket.

Stanhopea Season 2014

Stanhopea oculata ABG# 96-0801 flower, lateral view

Lots of activity buzzing around our Stanhopea collection this summer. Last year's newly divided plants are now big enough to carry capsules, so I've been busy pollinating our plants. In addition, photographic documentation of our collection is now possible with a newly developed image library that references our plant records database. (Thanks Michael Wenzel and Cindy Jeness: you guys are terrific!) So I have also started systematically photographing each Stanhopea accession.

Stanhopea oculata ABG# 96-0801 flower

For each accession, there will be six images that show morphological features that are diagnostic for Stanhopea. When an identification needs verifying, like this one, I send the images to Dr. Mark Whitten and Dr. Günter Gerlach.

Stanhopea oculata ABG# 96-0801 lip and column

As I learned from them, it's not always easy to put a name on a Stanhopea. The plant pictured here, which we received as Stanhopea oculata, is a good example. It has features in common with S. oculata, S. whittenii and S. dodsoniana. Which is it? S. oculata  varies enormously in the size and morphology of its flowers over its wide range (Mexico to Venezuela). Its fragrance is similar to several other morphologically similar species with whom it shares pollinators, making the existence of natural hybrids within populations likely. In fact, Rudolf Jenny states that S. oculata populations frequently consist of a mixture of both of the parents, natural hybrids, and back-crosses. So, is Stanhopea oculata five new species with some shared characteristics? Or do we treat it as one widespread species complex on its way to becoming new distinct species? What is Stanhopea oculata? And what the heck do I write on this plant's label?

Stanhopea oculata ABG# 96-0801 lip without column, dorsal view

Right now, there's not a good answer to these questions other than 'more work needs to be done.' For now our plant's identity remains as we received it: Stanhopea oculata ABG# 96-0801.

Stanhopea oculata ABG# 96-0801 lip, ventral view

In spite of the taxonomic uncertainty, I'm having a blast. Typically, I use the oldest flower on the inflorescence as the capsule parent and the youngest flower for dissection. Dissecting them inspires awe and admiration. These plants are so beautiful. It's a privilege to do be able to document them.

Stanhopea oculata ABG# 96-0801 column, ventral view

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.

Lycaste schilleriana var. rosea

Among all of our Lycaste species, this could be my favorite. Of the two or three dozen Lycaste species in cultivation, most fall within the traditional spring floral color spectrum--pinks, yellows, whites. Not this one.

This is Lycaste schilleriana var. rosea. I love the deep olive green of the sepals. They are olive on the exterior and bronze on the inside.

Even more remarkable is the extraordinary length of its sepals. Each sepal is about 3 inches long, giving L. schilleriana the widest flowers in the genus.

The buds look like elongated beaks.

Lycaste schilleriana var. rosea likes a greenhouse at the cool end of the intermediate temperature spectrum. For now, our plant resides in our shadiest most humid greenhouse right next to the wet wall, where the summer daytime temperature maxes out at about 83º. If the current warming trend continues, we may have to move it to the Tropical High Elevation House.

Lycastes are pollinated by Euglossine bees. Lycaste schilleriana is known from Panama and Colombia where it grows as a lithophyte at around 1400 meters elevation.