Archives For night pollinators

Darwin’s Orchid and the Wardian Case

History makes an appearance at the Orchid Show this winter

Mike Kwiatek —  February 26, 2014 — 1 Comment

There’s something very special about this orchid. Can you tell what it is?

PHOTO: Closeup of Angraecum sesquipedale bloom.

A native of Madagascar, Angraecum sesquipedale is an epiphyte that prefers the drier branches and trunks of trees as a host.

 

The nectar of this orchid resides almost entirely at the tip of the orchid's spur.

The nectar of this orchid resides almost entirely at the tip of the orchid’s spur.

If you guessed that it was the long tubular structure coming from the back of the flower, you are right! That spur contains energy-packed nectar and is the reason this plant has a place in history.

Discovery

Angraecum sesquipedale was first described in 1822 by French botanist Louis-Marie Aubert du Petit-Thouars and would be shrouded in mystery for decades after. It arrived in the United Kingdom 33 years later.

ILLUSTRATION: an illustrated plate of Angraecum sesquipedale from 1822.

An illustration of Angraecum sesquipedale from Histoire particulière des plantes orchidées recueillies sur les trois îles australes D’Afrique de France, de Bourbon et de Madagascar (1822) .

At the time  this orchid was discovered, transporting plants from one continent to another was extremely difficult and often unreasonable. The long sea journey, combined with polluted conditions in industrialized cities, made it difficult to collect and maintain specimen plants. This would all soon change.

It was in 1829 that Nathaniel Bagshaw Ward discovered the mechanism that revolutionized horticulture and botany forever. 

The Wardian Case

Nathaniel Bagshaw Ward was an English doctor who spent most of his life in eighteenth-century London. In his youth, he perused the writings of Linnaeus and spent some time in Jamaica, which fostered his love of entomology and botany. As an adult, Ward was inspired to create a wall of ferns and mosses in his own yard, but failed due to the polluted air of East London. He was distraught.

In the summer of 1829, Ward took a glass jar and placed a hawkmoth chrysalis inside, atop a bed of moist leaf mold. Ward regularly checked on the progress of the moth, finding that before it hatched, grasses and a fern emerged from the leaf mold. Ward observed that the glass jar retained moisture because as it warmed up, water evaporated, condensed on the glass, and returned to the base of the jar, never escaping. With this success he repeated his experiment and, to his delight, found that he could keep plants growing within the chamber for years. His discovery brought about the invention of the Wardian case, the predecessor to the modern terrarium. He wrote extensively about this in his book, On the Growth of Plants in Closely Glazed Cases. Soon the Wardian case became a popular feature of the parlor in Victorian society. These parlor versions, both tabletop and freestanding forms, often held one or more plants and could be rather ornate.

PHOTO: A large Wardian case, made of steel and glass—an individual greenhouse for an orchid.

One of four Wardian cases appearing in our Orchid Show this year. Wardian cases like this one could be found in parlors of wealthy Victorians.

In 1843, the Wardian case was used for the first time to bring plants from China by sea. The director of the Royal Botanic Gardens, Kew, observed that in 15 years, the Wardian case brought six times as many plants as had been imported in the last century. If you do the math, that means it made importing plants almost 40 times as efficient as regular ocean travel! This was of particular use to collectors like James Bateman, a wealthy landowner who sponsored several plant exploration trips through the Royal Horticultural Society. One such trip would bring several rare Angraecum sesquipedale from Madagascar to England, and in 1862, this plant would find its way to one of the prominent figures in history.

Charles Darwin

By 1862, Charles Darwin had already become a prominent figure internationally. Having published On the Origin of Species three years earlier, Darwin was already the subject of scrutiny by religious groups and scientists who disagreed with his theories on evolution and natural selection. In this same year that he received a number of orchids from Bateman, Darwin published his book The Various Contrivances by Which Orchids are Fertilised by Insects, which proposed that Angraecum sesquipedale must be pollinated by a “huge moth with a wonderfully long proboscis” (or straw-like tongue). He proposed that it might be a Sphingidae moth since these are typically large. No such moth was known to exist on Madagascar.

Though largely overlooked by the public, his proposal became a subject of controversy, particularly in the religious community. Critics attributed any existence of such a creature to be by divine will and not natural selection; most mocked the possibility of such a moth existing. Others viewed his prediction with skepticism since only smaller moths had been discovered in Madagascar.

PHOTO: Morgan's sphinx moth, with its 30-centimeter tongue unrolled to show its length.

Morgan’s Sphinx moth, the predicted pollinator. Photo by Esculapio (Own work) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons

In 1903, 21 years following Darwin’s death, a subspecies of moth known as Xanthopan morgani praedicta, Morgan’s Sphinx moth, was found in Madagascar. This moth has a wingspan of 5 to 6 inches and a proboscis of 10 to 12 inches long. The subspecies name, praedicta, was intended as an homage to Darwin’s prediction that such an insect existed.

Angraecum sesquipedale, frequently referred to as Darwin’s Orchid, is currently being displayed in the Greenhouse Gallery of the Orchid Show (purchase tickets here) this year.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

“Should we try to roll its tongue out?”

(Or, My Summer Vacation in New Mexico)

Sophia Siskel —  September 9, 2013 — 1 Comment
PHOTO: Sophia Siskel holds a hawkmoth caught at night while researchers look on.

Holding a toad-sized hawkmoth lured in by our sheet and black light.

O.K., I did know what a proboscis was before my trip to New Mexico last month. But learning how to uncoil a hawkmoth’s 3-inch nectar-sucking hollow tongue while trying to calm the toad-sized insect in my hand was the biology lesson of a lifetime. 

Thanks to Chicago Botanic Garden scientists Krissa Skogen, Ph.D., and Wes Glisson (who recently earned his master’s degree in plant conservation biology from the Garden/Northwestern University graduate program), and Bureau of Land Management (BLM) New Mexico state botanist Mike Howard, I learned about hawkmoths, the plants they pollinate, and how to collect plant cuttings for scientific study. 

I also had the opportunity to meet and work beside two remarkable interns, Kate Wilkins and Elisabeth Ward, from our Conservation Land Management Internship Program (and enjoy a few absolutely perfect hours of exquisite silence in the desert at the foot of the Guadalupe Mountains on the New Mexico/Texas border). 

PHOTO: Panorama of the New Mexican desert.

The exquisite silence and panorama of the New Mexican desert.

I had been asking around the Garden’s scientific staff to see whose fieldwork would fit with my summer schedule. Krissa was planning a trip to southern New Mexico to film an episode of Chris Martine’s great video web series Plants are Cool, Too. Krissa’s episode, which will air in October, highlights her work on long-distance pollinator movement, focusing on Oenothera harringtonii, an evening primrose endemic to southeastern Colorado and other closely related Oenothera species. The flowers of Oenothera harringtonii and many other evening primroses open soon after sunset and are pollinated primarily by hawkmoths. These moths feed on the nectar of Oenothera flowers, which they locate by the strong fragrance produced by the flowers. We commonly think of floral scent for its role in attracting pollinators, but it may also be used as a cue by floral and seed predators.

By studying the shape, smell, and color of Oenothera flowers, Krissa and her colleagues hope to determine what it is that attracts pollinators to these flowers. She can also determine how the plants “reward” their pollinators by studying nectar—how much flowers produce and how much sugar the nectar contains. And lastly, by collecting pollen grains from pollinators, Krissa can determine which plant species the pollinators rely on most, which brings me to catching hawkmoths and collecting pollen from their tongues.

PHOTO: Krissa gently rolls out the proboscis to show us just how long it is!

Krissa gently rolls out the proboscis to show us just how long it is!

The first night of our trip, we set out to find some hawkmoths. After visiting a couple of sites in the Organ Mountains, we found them. Above is a photograph of Dr. Krissa Skogen, Elisabeth Ward, and me holding the toad-sized moths we attracted to a blacklit white sheet held up on a PVC armature. 

After sunset, the hawkmoth uses its long hollow tongue to extract the nectar from deep down within the narrow mouth of the flower. The moth’s nightly journey often covers a distance as far as 20 miles. Krissa gently rolled out the tongue to show us just how long it is!

The next day, we set out early to collect Lepidospartum quamum for our colleague Evelyn Williams, Ph.D. Evelyn, a post-doctoral researcher, has been working with Jeremie Fant, Ph.D., Kayri Havens, Ph.D., and Mike Howard on this plant since 2012 in an attempt to figure out why it is threatened with extinction in this area of New Mexico. The plant grows in a unique environment—the gypsum salt flat.

PHOTO: Tagged plant cuttings in a small bowl.

Lepidospartum quamum cuttings, tagged and ready to be sent for propagation in our greenhouses.

Evelyn’s previous collecting trip this spring needed to be supplemented with new cuttings. We worked all day to collect the cuttings, which we sent back to the Garden for propagation in our production greenhouses, as well as samples for genotyping in the Garden’s Harris Family Foundation Plant Genetics Laboratory.

This important work, which ultimately aids seed growers, restoration practitioners, and government agencies to select appropriate plant materials to restore diverse plant and animal communities, was funded by a National Fish and Wildlife Foundation (NFWF) grant as part of the Native Plant Conservation Initiative.

It’s a fact that most people are more attracted to animals than plants—and therefore more inclined to know their names and fight for their survival. Just compare the following two photographs—the Lepidospartum quamum specimen we were studying, and this lizard that darted by and immediately commanded our attention (yes, even botanists and plant-lovers are drawn to a cute face).

PHOTO: A desiccated Lepidospartum quamum plant.

What grabs your attention more? This plant …

PHOTO: A cute lizard.

…or this cute lizard?

But all life depends on plants and the healthy habitats on which they depend. When we think of fighting to save wildlife, let’s remember that wildlife includes plants! I am hopeful that by working with collaborations from gardens, zoos, government agencies, and other land-trust and conservation organizations, we can integrate plants into wildlife action plans both in the U.S. and abroad. I particularly like how this report by NatureServe summarizes this issue.

We can all point to moments in our life—when we’ve experienced something new or met someone special—when our understanding of life changes. My two days with these five scientists—at all phases of their careers—was one of these experiences I will never forget.

PHOTO: The New Mexico research team.

Thank you, Krissa, Kate, Mike, Elisabeth, and Wes!

One last note: Hawkmoths are essential to ecosystems from Venezuela to here in Chicago. My son and I watched one this afternoon drink from the hostas on our street! Below is one we filmed in the English Oak Meadow of the Chicago Botanic Garden last week.

©2013 Chicago Botanic Garden and my.chicagobotanic.org