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.

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.

Identifying our Acineta

Great news: we have a name on our mystery Acineta. And it's not erythroxantha, the name that was on the label when we received it from a Panamanian grower. In order to make the determination, it was necessary to dissect a couple of flowers and send photographs to Dr. Günter Gerlach at Münich Botanical Garden. He was very specific about which floral parts he needed to see. Here is what I sent him.

Shown above, I've removed two lateral sepals and one of the lateral petals in order to show the lip in side view. Each side of the lip has two deep incisions, creating a side lobe. The column is white and partly hidden by the lip.

Next, I made a longitudinal cut through the lip to show it in cross section. The interior has blood red spots. You can see the callus, chair-shaped and white in cross section.

Then, I removed a second flower and cut off everything but the the lip and the ovary. Above, you can see the lip, face up. It is shaped like a shallow scoop. Just above the broadly U-shaped edge of the lip is the callus, which is wide and thin seen from above. The lip and callus are important diagnostic features.

The underside of the lip.

The pollinarium, including two pollinia and a sticky orange viscidium.

This must have been an easy call for Dr. Gerlach, who described this species, Acineta mireyae, in 2003. Additonal photos appear on his amazing Stanhopeinae image data base, where you can compare A. mireyae with some closely related Central American species, Acineta sulcata and Acineta sella-tucica. In fairness to the grower from whom we purchased our plant, I should mention that it was shipped to us in 2002, before publication of the epithet mireyae. Our thanks to Dr. Gerlach for solving this mystery!

Open at last... But what is it?

It's not very often that we flower an Acineta, so there has been tremendous anticipation as the spike of this Acineta erythroxantha has elongated to an astonishing 28 inches. Bud development has been agonizing. ('Slow as Christmas' is the phrase around here.) But at last we have open flowers. And a surprise...

This isn't actually Acineta erythroxantha at all, as the label would indicate. The lip is very different. We received this plant in 2002 as A. erythroxantha from a Panamanian source. Could this be the Panamanian species, Acineta mireyae?

For an answer, I'm turning to Dr. Mark Whitten at University of Florida-Gainesville and Dr. Günther Gerlach at Münich Botanical Garden, rockstars of Euglossine bee-orchid research. Acineta identification is tricky and I want a definitive answer. Dr. Gerlach is the author of the original 2003 publication of  A. mireyae, so I'm sending pictures of these flowers, dissected. We'll see what he says.

Acineta belongs to the Stanhopeinae subtribe, and like Stanhopea, they are pollinated by Euglossine bees of the genus Euplusia.

The waxy fragrant flowers are carried on a pendant raceme. The sepals and petals form a hood around the column, creating a tunnel for the bee to enter. The bee obtains the fragrance by scratching at the base of the lip inside the tunnel. As the bee backs out, the viscidium of the pollinarium is stuck to the bee's scutellum. If the bee enters another Acineta flower, the pollinia are placed on the stigma as the bee backs out, and thus the flower is pollinated.

Cattleya maxima

Late summer often brings an ebb in flowering in everyone's garden. Not here. Late summer is one of the most interesting seasons in the Fuqua Orchid Center. Now is the time to see stanhopeas, anguloas, miltonias, catasetums ...and lots of Cattleya maxima, an outstanding late summer species.

Cattleya maxima grows as an epiphyte or occasional lithophyte in lowland and highland forests from 10 to 1500 meters in Venezuela, Colombia, Ecuador and Peru. In the southern hemisphere (where long days coincide with Christmas) it is known as Flor de Navidad, the Christmas Orchid.

Stanhopea Season

Stanhopea embreei

Which are the best smelling orchids? Stanhopeas get my vote every time. Vanilla, chocolate, wintergreen. One of our stanhopeas, I discovered last week, has a fragrance that my nose recognizes as cinnamon.

Stanhopea tigrina

Our stanhopeas are knocking themselves out this year. If one Stanhopea plant smells like vanilla cream icing, imagine a half dozen flowering simultaneously. Some afternoons the Orchid Display House smells like a bakery. (Until you get to the bulbophyllums, that is).

Stanhopea tigrina (above) has a fragrance that is 90% phenyl ethyl acetate, a not uncommon floral constituent described as very sweet, rosy, fruity and honey-like. You can actually buy it online. However, the fragrance of Stanhopea tigrina is complex and is dominated by other compounds, like raspberry ketone and vanilline and courmarine, giving it a sweet-spicy scent unique among orchids. Stanhopea tigrina grows on the Atlantic side of Mexico.

Stanhopea tricornis

Stanhopea tigrina is known as El Toro in Latin America on account of the horns projecting from either side of the lip. In fact, most of the 55 or so species of Stanhopea have horns. The horns guide the pollinator, a fragrance-collecting male Euglossine bee, toward the pollinia located at the end of the downward arching column. Stanhopea tricornis  is one of a handful of stanhopeas without horns on the lip.

How to Grow Habenaria rhodocheila

Red lipped. An unexpectedly glamorous epithet for a small playful looking orchid. And although rhodocheila means red lipped, there are actually many color forms of Habenaria rhodocheila, including orange, yellow and various shades of pink and red.

I find this plant irresistible, whatever the lip color. And it's not hard to grow. Here's what you need to know.

How to Grow Habenaria rhodocheila

Habenarias are perennial plants that grow from tubers. There are hundreds of species; some grow in temperate climates, others in tropical climates. Habenaria rhodocheila is one of the tropical species from southeast Asia. It grows in areas that have a dry season. In order to cultivate it successfully, you have to accommodate its annual growth cycle.

ANNUAL GROWTH CYCLE Habenaria rhodocheila produces a new shoot in late spring and flowers in late summer. After flowering, its leaves continue to photosynthesize for a few months while the plant stores carbohydrates and starch in the underground tuber. In late fall the foliage shrivels, leaving only the underground tuber to sustain the plant while dormant.

SPRING
Water: The appearance of the new leafy shoot is your cue to gradually increase the frequency of watering as the leaves expand and the root system grows.  In spring the potting medium dries out slowly, mostly from surface evaporation. Until the leaves expand, the plant doesn't have enough leaf surface area to lose water via transpiration; so it's not taking up much water from the medium. Let the medium become almost completely dry, then water deeply.
Light: 80% shade. 800-1500 footcandles. Eastern exposure shaded from strong sun.
Temperature: 58º F (night minimum); 80º F (day maximum).
Fertilizer: Not yet.

SUMMER
Water: By the time the plant has its full complement of leaves, the medium should be saturated regularly, when the upper 1" is barely moist. In our greenhouse, where the plants receive continuous strong air flow from a circulation fan, this is about twice a week. Under other conditions, it may be less frequently.
Light: As above.
Temperature: As above.
Fertilizer: Once the plant has some fully expanded leaves, apply a balanced (roughly equal percentages of nitrogen, potassium and phosphorus) fertilizer at half strength every two weeks.

FALL
Water: Don't be alarmed in fall when the leaves start to turn brown. This is your cue to gradually decrease the frequency of watering. Allow the plant to dry out before watering. Allow the leaves to remain on the plant until they have withered completely.
Light: As above.
Temperature: As above.
Fertilizer: None.

WINTER
Water: By mid winter the plant should have no leaves at all. Water deeply, but only as often as is necessary to keep the tuber from shriveling. Allow the soil to become bone dry, but don't let it stay that way for more than a few days. In spring, before the onset of new growth, remove the tuber from the pot, cut away the dead roots, and repot in a 4" pot with plenty of drainage  holes. Soil-less media for tropical terrestrial orchids typically contains some combination of fine grade fir bark, charcoal, perlite and sphagnum moss.
Temperature: Above 50º F.

Light & Fertilizer: None.

Habenaria rhodocheila is so rewarding and, actually, less work than an evergreen tropical orchid. Most of the work involves learning its growth cycle. How hard is that?
Want to know where to get one? Tropical Orchid Farm is a good place to start.

Pretty in Pink

Only a handful of the 600 or so species of Habenaria are in cultivation. Habenaria rhodocheila is one. Habenaria medusa is another. Most Habenaria live happily obscure lives in the understory of forests and in grasslands scattered across six continents. Few appear alongside cattleyas in the glossy pages of catalogs or websites. How come?

It's the dormancy thing. Like many terrestrial orchids from seasonally dry habitats, Habenaria species drop their leaves and go dormant for a few months. And many growers, when offered a pot devoid of foliage, will hesitate. There is a tuber in there, right? Still? How often do I water a dormant tuber? And how much?

As a potted plant grower, I have a deep appreciation for orchids that go dormant. No leaves for six months? Fine. No leaves means no scale. Infrequent watering? No problem. I'm gathering all my Habenaria pots together and sticking a great big sign in their midst: Let Us Dry Out! Then I go pay attention to their leafy relatives with scale.

Habenaria rhodocheila is one of the prettiest orchids we grow. It glows pink. Every time it (or one of the other color variants) is offered for sale, there is a stampede among professional growers to be first in line. Don't be intimidated by the dormancy requirement; and check back tomorrow for the How to Grow tips.

Lycomormium

Lycomormium is closely related to Peristeria--the Dove Orchid and its relatives. Like Peristeria, Lycomormium plants can be large, are often terrestrial, have robust pseudobulbs and long pleated leaves. The flowers are simple (compared with other Stanhopeinae); and they are pollinated by Euglossine bees. Unlike Peristeria, Lycomormium has a lip (dark pink in the unidentified species above) that is fixed, not hinged.

The name Lycomormium comes from lykos, the ancient Greek word for wolf; and mormo, meaning goblin --a sinister name for group of orchids most of whom have rosy pink polka dots.

Lycomormiums are Andean orchids that grow in wet lower montane forests in Colombia, Ecuador and Peru.

Our lycomormiums struggled through last summer, when we had four consecutive months above 95º. Ninety five degrees outside translates into 85º to 88º (depending on the %RH) in our humid greenhouses. Oh no, I thought, if this trend continues will we have to give up growing intermediate orchids?? So we moved our lycomormiums to the cool end of the greenhouse next to the wet wall and hoped for the best. But surprise, this summer has been cool, cloudy and rainy --hardly two days in a row above 90º-- and the lycomormiums look much happier. We're not crazy about cloudy, but cool is a welcome novelty here.

Ginger Orchid

If you're visiting the Fuqua Orchid Center this week you really need to take a moment to inhale this orchid, Clowesia russeliana. My nose says ginger root, one of my favorite scents in the Catasetinae (the subtribe containing Clowesia, Catasetum, Cycnoches and Mormodes). Delicious.

Clowesia russeliana grows as an epiphyte at 600 to 1000 meters elevation in seasonally dry open forests from Mexico through Guatemala, Honduras, Nicaragua, Panama to Venezuela. Our plants drop their leaves in October and remain leafless through their dormancy.

August through October is the best time for fragrance in the FOC. In fact, the Orchid Display House smells like a cookie factory this week, with five species of Stanhopea, four species of Catasetum, a Lycomormium, a Coryanthes and our ginger orchid, Clowesia russeliana, on display. Be sure to stop by!

The Dove

The Dove Orchid (Peristeria elata)  must be one of our most popular orchids. People actually stop me and ask for it by name. Our Dove Orchids flower every year in August and September; they are flowering  now in the Central America area in the back of the Orchid Display House.

The generic name, Peristeria, comes from the Greek word for dove (peristerion) and refers to the appearance of the flower. If you look inside, you can see that the column and lip are fused in the shape of a dove--the head and beak are formed by the anther cap; the neck by the arching column, and the wings and tail by the three-lobed lip. There are six to twelve Peristeria species (depending on who you you ask), so broadly speaking, they are all dove orchids.

Peristeria elata is the national flower of Panama, where it is known as 'Flor del Espiritu Santo'. Because of its popularity the Dove Orchid is now a very rare species in Panama, where it used to be abundant.

Unlike many other Peristeria species Peristeria elata grows terrestrially, rather than as an epiphyte, in the transitional zone between grass savanna and forest.

Peristeria elata is another of our Euglossine bee pollinated orchids. The waxy ivory colored flowers have a sweet and slightly resinous fragrance. The fragrance has a simple structure. It has two main components, both perceptible to people-- eucalyptol and phenylethyl acetate.

Like other Euglossine bee pollinated orchids, Peristeria has an elaborate mechanism to ensure pollination. The flower's lip (the wings and tail of the dove) is hinged. Upon landing, the bee's weight tips the lip and he is thrown against the column (the head and neck of the dove). The side lobes of the lip (the wings) hold the bee, and the pollinarium is attached to his thorax as he struggles to leave.

Peristeria pendula

If Peristeria elata, the Dove Orchid, is the only Peristeria familiar to you, then Peristeria pendula will come as a surprise. Superficially it looks very different. The flower spike is compact and pendant, so the flowers are clustered on the surface of the potting mix like a clutch of speckled birds' eggs. It's only when you look inside the flower and see the hinged lip that you realize that you are looking at a Peristeria. You can see another species here.

Peristeria pendula is an epiphyte that grows in wet forests at 500 to 1100 meters across northern South America. Our plant flowers in August. Since it is an epiphyte we grow it in a different medium and a different pot than the one we use for Peristeria elata, a terrestrial orchid. For Peristeria pendula we use a mixture of long fibered premium sphagnum and chopped tree fern inside a net pot.

The Return of the Medusa

Any plant with the epithet medusa on its label has my immediate attention. Medusa is a name that promises weirdness--fringe, hairs, snaky appendages-- something exceptional.

Habenaria medusa flowers every August in our greenhouses, and it is exceptional, and weird, but without the scariness that the name suggests. The flower's lip has three lobes. The two side lobes are deeply incised and look like fluttery fringe. Each flower has a long spur.

You might think that something so ethereal must be difficult to grow. Not true. It's actually pretty foolproof if you can remember to ease off the watering for a couple of months after the flowers finish. By then the plant has enough reserve stored underground to withstand the seasonal drought that it would receive annually in its native grasslands-- usually lasting several months. In the greenhouse we reduce the frequency of watering from about every four days to about every ten days while the plants are leafless. Our cue to resume frequent watering is the emergence of the new leafy shoot.

We Get Big

Not all of our Grammatophyllums are super sized. We have quite a few junior sized plants, like this Grammatophyllum scriptum f. citrinum in our back up greenhouse. And by junior sized, I mean fifteen pound plants producing four foot spikes. Grammatophyllums get big.

Grammatophyllums are easy to grow if you have very bright light, a warm to hot greenhouse, and, naturally, lots of space. We grow ours on top of the cedar pergola in the Orchid Display House where they can bask. In the backup, they grow alongside the heat loving Brazilian Laelias.

During the growing season, a Grammatophyllum produces an abundance of upward growing spear-like trash basket roots that trap nutritious organic matter. The grower in me lives for this. To me, the production of a bumper crop of these amazing roots is every bit as gratifying as a flush of flower spikes.