Archive for February, 2016

An Emerging Spectacle: Orchids in Focus at the United States Botanic Garden

The Bletillas are nearly in bloom, and we all know what that means—the annual orchid exhibit is upon us! This week’s post is a special preview of the exhibit, Orchids in Focus, which is produced in partnership between the United States Botanic Garden (USBG) and Smithsonian Gardens and opens this Saturday, February 27 and runs through April 17.

Some of my favorite orchids to photograph are the ones with barely emergent flowers. There is a sense of anticipation in the sight of unfurling petals, like those of the terrestrial Bletilla striata. Developing flowers often display curious shapes that remind us (like so many things) that there is a special beauty in the journey. Brassidiums are some of the best exemplars of this, since their elongated flowers have to unfold from buds that are the size of a fingertip.

Orchids in Focus, which features plants from the Smithsonian Gardens Orchid Collection and the USBG’s collections, is also emerging from its so-called bud. My visit to the conservatory this past Wednesday found a flurry of activity in the East Gallery and finishing touches being put into place in the main Garden Court.

IMG_7715

I was able to catch up with a former Smithsonian Gardens intern who is now an orchid grower at the United States Botanic Garden. Justin gave a tour of the work-in-progress and it is clear that it will be quite a spectacle.

The exhibit’s theme highlights orchid photography and is surprisingly interactive since the photography in question is not only images you look at on the walls, but also what YOU take during your visit. Large frames have been constructed in the Garden Court for visitors to pose behind as they are “framed by orchids,” and another station for “orchid selfies” has been designated in front of two exquisite green walls. According to Justin, each side of the green wall takes five hours to build since orchids must be placed individually in the small pockets covering the surface. It sounds like a painstaking process, but the result is magnificent.

The East Gallery houses a tropical forest display which will feature terrestrial orchids from the understory and epiphytic orchids from the canopy on respective sides of the room. Over the next couple of days, USBG staff will be working hard to complete the exhibit, those last few flowers will finish opening, and your job… build anticipation, and get those cameras ready!

Julie Rotramel, Living Collections Specialist

February 26, 2016 at 9:45 am Leave a comment

What Time Is It? Garden Time!

Floral clocks started appearing in outdoor public spaces at the turn of the twentieth century. Not to be confused with botanist Carl Linnaeus’ flower clock which laid out a variety of flowers in a clock-like design according to the hour of the day they opened and closed, the floral clocks referred to here were large-scale timepieces placed amongst richly colored and contrasting carpet plants in elaborate patterns. Some worked like sundials, dependent on the sun to mark time, while others were fully functioning timepieces.

The design for one of the earliest floral clocks, at Edinburgh’s Princes Street Gardens, is credited to Parks Superintendent John

McHattie who arranged to have clockmakers Ritchie & Son install the necessary mechanical parts. When the clock began operating in 1903, it had only an hour hand; a minute hand was added the following year. The Princes Street Gardens’ floral clock featured a twelve-foot dial and hands created from long, shallow troughs of sheet metal planted with flowers. It was not only a work of ingenuity for masterfully combining the technology of clock making with the art of garden design, but also for the engineering it took to install the clock on a forty degree incline.

princes street gardens clower clock

Princes Street gardens Floral Clock in Edinburgh, Scotland, between 1920 and 1940. Smithsonian Institution, Archives of American Gardens, J. Horace McFarland Collection.

Floral clocks were regularly showcased at world’s fairs and in public spaces ranging from parks to cemeteries around the turn of the century. They were perfect for ornately planted Edwardian-era carpet beds that featured sometimes over-the-top figurative designs such as historic scenes, lettering, or coats of arms. In America there were floral clocks displayed on the slope of the Agricultural hill at the Louisiana Purchase Exposition. Water Works Park in Detroit Michigan featured a water powered floral clock and by 1948, America was home to the world’s largest floral clock in Fort Lincoln Cemetery in Brentwood, Maryland, which still operates today.

Louisiana Purchase Exposition flower clock

Stereograph of the Great Floral Clock in front of the Agricultural Building at the Louisiana Purchase Exposition in 1904. Smithsonian Institution, Archives of American Gardens, Historic Gardens Stereograph Collection.

Floral clocks have their place as a trend or fad in gardening history and are wonderful examples of the use of technology in the garden. The ability of landscape architects, gardeners, and clock makers to collaborate on such beautiful and yet demanding pieces is what makes the floral clock so special.

-Jessica Brode, Archives of American Gardens Intern, Smithsonian Gardens

Original version of this post published on the Smithsonian Collections Blog.

February 12, 2016 at 10:00 am 1 comment

An Exploration of the Fringe: What’s Blooming in the Smithsonian Gardens Orchid Collection

Winter is one of the most prolific bloom times in the Smithsonian Gardens orchid greenhouses and each year I am astounded by the diversity that is on display. I have a predilection for miniature orchids, for bizarre traits and unique stories and the two orchids featured today will not disappoint.

Bulbophyllum saltatorum var. albociliatum is an exquisite species found widely across Central Africa. Its winter-blooming flowers are no bigger than a thumbnail, and like many Bulbophyllums, the lip has been dramatically modified. In this case, the modification takes the form of a bright pink fringe, which acts as a lure for small flies who end up inadvertently pollinating the flower.  This species is also rather unique for a Bulbophyllum because its scent is quite pleasant (at least to my olfaction).

IMG_1601

Fringe is not purely used for deceptive purposes. This characteristic, along with colorless flowers and night fragrance is a pollinator syndrome for Hawk Moths. Various species of Brassavola and Habenaria exhibit a unique variation of this morphological adaptation, and offer nectar rewards to their nocturnal visitors. It is not certain what characteristic of this fringed lip appeals to the Hawk Moth, but the convergence of this trait across unrelated orchid genera implies that it is pollinator specific.

In their infinite diversity, orchids always manage to deconstruct the carefully deduced generalizations scientists make about their biology. The Clowesia below, Clowesia Grace Dunn, is a hybrid between Clowesia rosea and Clowesia warzewiczii and as you can see, has an arresting display of fringe on its lip as well.

IMG_7585

These flowers are NOT moth pollinated, rather they are visited by crepuscularly active Euglossine bees that collect their fragrances in the form of oils to woo lady bees. Typically, Euglossine bees are generalists, and will collect fragrances from a number of different species. It has been theorized that the fragrances of Clowesia species change throughout the day, with an “optimal fragrance” either before dawn or just after dusk when their pollinators are most active. This may seem like a wild concept, but many biological functions occur in a cyclical fashion, and solely night fragrant orchids are commonly referenced. It makes sense that the same mechanism would be at work in crepuscularly, diurnally and nocturnally fragrant plants.

Daily fragrance fluctuations are not unique to Clowesia, and have been studied previously in Arachnis, Vanda, Spathoglottis and Oncidium (Goh, 1983), among others. The variation in fragrance could be influenced by changes in acidity due to CO2 production during Crassulacean Acid Metabolism (Goh, 1983) and is decidedly affected by photoperiod, an indication that fragrance is regulated by a circadian rhythm (Altenburger & Matile, 1990).

I never considered the importance of physiological constraints playing such a vital role in the evolution of plant-pollinator relationships, but evidence for this “biological clock” of fragrance emission throughout the plant world is incredibly fascinating. Orchid pollination is a beautifully complex fabric of not only interactions (deceptive or otherwise), but the timing of these interactions. As I am often reminded, NOTHING is coincidence, but the intricacies of evolution often seem astoundingly fortuitous.

 

Julie Rotramel, Living Collections Specialist

References:

Altenburger, R., & Matile, P.. (1990). Further observations on rhythmic emission of fragrance in flowers. Planta,180(2), 194–197. Retrieved from http://www.jstor.org/stable/23380097

Goh, C. J.. (1983). Rhythms of Acidity and CO2 Production in Orchid Flowers. The New Phytologist, 93(1), 25–32. Retrieved from http://www.jstor.org/stable/2431891

February 5, 2016 at 12:18 pm Leave a comment


Enter your email address to follow this blog and receive notifications of new posts by email.

Join 321 other followers

Visit our Website!

Recent Posts

February 2016
M T W T F S S
1234567
891011121314
15161718192021
22232425262728
29  

%d bloggers like this: