Archive for the ‘Botany’ Category

The Paradox of Sugaring

By Laura Yayac

saptap (1)It flavors creemees, cotton candy, and liqueurs. It’s poured over pancakes and snow, and is used in countless recipes. And right now, the raw sap is running from trees into buckets and webs of tubing then onto sugarhouses, where it’s boiled into maple syrup in all its amber glory.

Sap runs when the nights are cold and the days warm, but something about this does not make sense.

Before I get to that, though, a bit of history. European settlers learned about maple sugaring from native tribes, who in turn have a variety of legends as to how they discovered that maple sap could be boiled into a liquid sugar. Written accounts of maple tapping date from the 1550s, and it isn’t just people who love maple syrup. One of the explanations for human discovery of syrup is watching red squirrels (Tamiasciurus hudsonicus). These critters have been documented using their teeth to cut into sugar maples, then returning over the next few days, after much of the water has evaporated, to lick the sweet blobs that are left behind.

Most Vermonters know the story and process of sugaring, but I’ll offer a refresher for those who, like me, did not grow up next to a sugarbush. Sugar maple (Acer saccharum) trees are the type most commonly tapped. Sap flows through the sapwood of the tree, the layer between the bark and the center heartwood. In the fall, trees turn their sugars into starches to store them in their roots and trunk for the winter. In early spring when the days are above freezing the starches are returned to sugars and the sap begins to flow. In a tapped tree, it flows out of the tap, and it is then drawn back up into the tree at night when the freezing temperatures return. Recent innovations such as a one-way valve for tapping, patented by Tim Perkins of the Proctor Research Center, help to keep microorganisms from being pulled back into the tree when this occurs.

But wait. If raw sap is 98% water, shouldn’t it expand when it freezes, and therefore be pushed out of the tree rather than pulled back in at night?

Maples are unusual among tree species in that the cells surrounding their vessels (the sap-carrying veins) are filled with gases instead of liquids. During freezing temperatures, the carbon dioxide (CO2) in these spaces contracts, creating room for the sap to move out of the veins and into the surrounding cells. As the sap does this, more sap is drawn up to replace it. (Other tree species have liquid-filled cells, so during freezing temperatures at night, the liquid-filled cells and the sap freeze. Because the sap has no open cell to move into, and it expands as it freezes, any sap that remains in liquid form is expelled).

When temperatures rise above freezing during the day, a combination of forces propel the sap out of the tree. Expanding CO2 gas bubbles push the frosty sap out of the cells and gravity pulls liquid sap down into the sugarmaker’s tubes. It’s from this harvest that 40 gallons of sap are boiled down to one gallon of maple syrup, and that Vermonters can once again revel in all things maple.

With help from: http://maple.dnr.cornell.edu/produc/sapflow.htm and http://www.uvm.edu/~uvmaple/maplesapexudation.pdf

Photo by Bryan Pfeiffer.

Laura Yayac is an Ecological Planning student who uses maple syrup in as many recipes as she can.

Winter Blooms

By Matt Pierle

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Cabin fever have you ready to see flowers again? If so, you’ve got options: Brazil and Bali are nice this time of year. Or seek out plants at a world-class botanical conservatory in, say, Montreal, London or San Francisco.

If you’re short on time or prefer shoestring travel though, you could do what I did over spring (technically late winter) break and book a $26 ticket on the Megabus from Burlington to Boston. From South Station Boston walk north to Chinatown, through Boston Common, past the frozen Frog Pond, to the Longfellow Bridge, over the Charles River to Cambridge and kick it up Broadway to Harvard Street. Continue north all the way to the Harvard Museum of Natural History.

In bloom you’ll find the extensive Ware Collection of Glass Models of Plants created by Czech born Leopold Blaschka and his son Rudolf. Most people simply call the collection “The Glass Flowers.” You read that right. This collection is not of flowers under glass, it is of flowers made of glass.

These life-size and larger-than-life specimens are more than impressionistic representations of garden blossoms; they are über-accurate botanical sculptures of a diversity of wild and cultivated plants. The pieces will challenge your powers to believe that something so realistic could be made from inert, colored sand.

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Who were the Blaschkas? How did they do it? And how did Harvard acquire these pieces?

The Blaschkas’ craft was not glassblowing. These pieces were created through a process called flameworking or lampworking. Glass rods were heated with the aid of paraffin and alcohol lamps, then cut with specialized scissors and shaped with tweezers, prods and other tools. Fine cooper wire provides structure for some of the daintier botanical structures, although I never once noticed the hidden metal armatures. Originally the pair worked with clear glass and then painted the models. Later they employed colored glass from the get go. Their eye for color was refined, to say the least, and a hundred or so years of display at the museum does not seem to have compromised their luster.

The artists, who worked without assistants or apprentices, came from a strong tradition of glasswork, a trade well established in their native Czech Republic. Indeed, Leopold’s father had also been a glassmaker. After Rudolf’s birth in 1857 Leopold moved the family to Dresden and established a workshop there.

From as early as 1863, Leopold earned a reputation for crafting museum quality glass invertebrates, mostly marine inverts, everything from jellyfish, and mollusks to sponges and corals.  The lifelike pieces were and are held by universities, museums and aquaria the world over – a few of which can also be seen at the Harvard Museum of Comparative Zoology.

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Leopold Blaschka experimented with plant models between 1860-1862 prior to making the marine models. These early plant models went from one owner to another before eventually being destroyed in a museum fire in the city of Liege, Belgium. In 1876 Rudolf started working full-time with his father. The Blaschkas spent the next ten years focusing on marine works for until they were approached by Dr. George L. Goodale who asked them them to make a few glass plants for Harvard.

Dr. Goodale was a plant physiologist and then curator of the herbarium at Harvard. After becaming familiar with the Blaschka’s impeccable work he traveled to Europe to meet them. Goodall wanted to have plant models that would endure for teaching and demonstration purposes. The Blaschkas shipped some pieces to the U.S. on speculation. In spite of being damaged in New York by customs inspection, Goodale showed the floral pieces to the Elizabeth Ware and her daughter Mary. The Ware women were sufficiently impressed. They generously offered to fund all aspects of the artistic production of more plants in honor of their late husband and father Dr. Charles Ware, a graduate of Harvard Medical School.

According to Jennifer Brown, the collection manager, Goodale hoped there would be at least 50 pieces created. That was 1886. Over the next 50 years the father-son team produced for Harvard around 4,300 individual pieces representing 787 distinct plant species.

The pair worked from plant specimens and cuttings sent from Harvard, from live material planted around their estate and from botanical drawings. While Leopold Blaschka remained in Europe, Rudolf traveled to the Americas in 1892 and then again in 1895. On those trips, he visited the growing collection of glass flowers at Harvard and did botanical drawings in the U.S. and Jamaica.

Packed in cardboard boxes with tissue paper and excelsior (wood wool), surprisingly few pieces were damaged in transport across the Atlantic from Germany to the U.S.

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At Harvard, the glass flowers are displayed in the style of herbarium vouchers

Each plant’s common and Linnaean name is shown on a tag, and smaller tags interpret oversized plant parts along with the degree of magnification (two to several hundred times). In this way, plant structures not easily seen with the naked eye are clearly displayed.

Peer into the throat of an iris to see the fine hairs lining the inner surface of the petals. See how the Nerf-football-sized male flower of a bat-pollinated banana plant dwarfs the dozens of female flowers that will develop one of our most globally important fruits.

Along with floral structures and fruiting bodies and non-reproductive plant parts like roots, leaf buds, and trichomes are presented in all of their fine scale glory.

Because of Harvard faculty interests in economic botany, later productions by the Blaschkas focused on cultivated plants from palms to figs, and from coffee to cacao.

There is even a rotting fruit series that depicts in jaw dropping accuracy stone fruits with fungus damage and apple fruit with cutaneous scab infections. Pieces emphasizing pollination feature flowers lacking one or more petals in order to show in graphic detail how foraging bees facilitating the transfer of male gametes from one plant to another.

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Exquisitely lifelike and, even to a botanist’s eye, beyond botanical reproach, the glass flowers will at once delight and educate you

Delicate flowers, tangles of roots and fresh leaves are all created as if by cloning. Goodale’s interest in having a collection of precise teaching specimens has been realized.

While several glass artists have tried, no one has replicating the exacting accuracy that the Blaschkas achieved. It’s not surprising that people arrive to Cambridge from all over the world to see these masterpieces and that many suggest that a divine energy or touch must have guided their creations.

If you’re a lover of plants, sculpture or hyper-realistic art, this is a collection you’ll want to see for yourself. Kids to seasoned botanists alike will appreciate the gallery, and the nice thing is, no matter which month you visit, the glass flowers are guaranteed to be in bloom.

Right now, it could be the perfect cure for cabin fever.

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Matt Pierle is a Field Naturalist candidate at the University of Vermont who has botanized from California to Cambridge. 

Special thanks to Collection Manager, Jennifer Brown, Herbarium Co-Director, Dr. Charles Davis and Gallery Volunteer, David Donovan. All photos by Matt Pierle with permission from the Harvard University Herbaria and Harvard Museum of Natural History.

 

 

 

 

 

 

Beyond a Collection of Facts

By Clare Crosby

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I spent my childhood hosting acorn cap tea parties for fairies, scurrying on calloused feet to collect eggs from the chicken coop, and reenacting Little House on The Prairie in the meadow behind my house, just east of Austin, TX. I did not suffer from “Nature Deficit Disorder.”

But as I grew, my interests shifted. I traded the meadow for well-manicured athletic fields and our old pond for swimming pools. My interest in my Central Texas natural surroundings paused around 8 years old. I never figured out what species of oak provided teacups for my parties, only that the caps were nicely proportioned for fairies. Neither did I learn what type of moss my fairies used for seat cushions, only that it opened into minute stars under sprinkled water.

I’m embarrassed now, as a naturalist, to admit that I don’t know even some of the most common species of my home state. This lack of knowledge, however, offers opportunity when I return to Texas from Vermont, the home of my formal ecological education. As I walk old trails and come across a familiar (yet unknown) tree, my inclination is to turn to field guides or a trusted expert to tell me what to call it, who eats it, and what it might reveal about the soil beneath it. In Vermont, I have had a string of wonderful professors and peers to teach me about the natural world, assisted, of course, by an ever-growing library of field guides. I hope to be so lucky again in Texas.

This time around, however, I am resisting my urge to immediately consult the experts. I am allowing myself to make a few discoveries.

So today I went for a walk not with my field guides, but with a pair of scissors and my mom, who admires nature through eyes much more artistic than my own. We collected a few specimens, returned to our kitchen table, and settled in with our pencils, watercolors, and tea. I chose specimens that were familiar from childhood memories, but not known to me as a naturalist.

I watched my mom lovingly render each thorn on a briar that had caused me many childhood tears. My old hatred melted into fascination, then respect. Inspired, I shifted my focus to the specimens before me.

I found that Texas mountain laurel—whose “hot beans,” my brothers knew, heat up enough when rubbed on rough stone to induce shrieks from little sisters—holds its leaves into late December. The terminal leaflet, at least in the sample I selected, lists to one side. The woody, wrinkled seedpods are difficult to open before their time and the beans within, fire engine red in my memory, can also be nearly black.

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As I sketched a species of elm, whose name I do not know, but which grew in the front yard of my childhood home, I noted that the bases of the small leaves are not dramatically asymmetrical like the Vermont species of elm. The delicate twigs of a sapling bend substantially at each minuscule leaf bud. Both the green and yellow leaves are sandpapery. The largest brown patches appeared confined by the leaves’ venation.

Perhaps I could have learned most of this from a book, a class, or a friend. I would have missed some details, though, along with an opportunity for connection.

Often as a naturalist I have learned only the characteristics that will allow me to distinguish one plant from others. This is, of course, useful. However, we protect what we care about and we care more when we have some sense of ownership or a personal connection beyond a collection of facts. So today, with my mom, I wanted to get to know my childhood acquaintances more intimately, moving past the strictly functional. I wanted to find companions for my fairy teacups and warm eggs. While it may not be a skill to add to my resume, I know that this afternoon spent sketching with my mom has made me a more inspired steward of the world around me.

In addition to being a Field Naturalist and Ecological Planning student, Clare Crosby is a connoisseur of board games. 

Roasting (and Restoring) Chestnuts

By Kat Deely

320px-American_Chestnut“Chestnuts roasting on an open fire.
Jack Frost nipping at your nose….” 

These words invoke every shiver of childhood anticipation for Christmas morning. Family time, feasting time, vacation time, and of course, presents time. I’ve been hearing these words sung every holiday season since before I can remember, and they have magically dropped me into a snow-globe world. So, it is with a bit of humility that I must admit something. I’ve never roasted chestnuts on an open fire. I’ve never roasted chestnuts on anything. I’ve never eaten a chestnut! And I bet I’m not alone. So how is it, this iconic Christmas classic’s first line is complete balderdash to the holiday seasons we know today? Read More

A Prayer for Monarchs

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By Rob Rich

The flaring wings or the breezy wisps of aspen and birch are few today. Gone are the flights of spring, but at Mobbs Farm in Jericho autumn is in flight. Apples and acorns plunk down with minimal elegance, but the swirling leaves trade the birds for brightness in the distant wood. And across the rusty meadow, others waft down lightly before winter. This is a day for milkweed, hinting at flurries to come.

They glide with a powdery lift by a pappus – the Greek for “old man” – providing cottony parachutes for each kernel. Soft, green pods once held them moist and tight, but now they are freed as they crack in the crisp, dry wind. The pods tear apart, opening for each white pappus to glisten like eyes in the gaze of the sun. They lift with a grace that seems to laugh at gravity. But failing to plant in the sky, they finally fall. I wantonly tear at some unopened pods, eager to help the silky strands find a resting place on earth.

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Apples Right Side Up

By Kelly Finan

In the fading light of mid-October I’m suffering from apple exhaustion.

Apples floated before my eyes as the first fallen leaves dusted my route from Vermont to Pennsylvania. I raided my father’s apple tree with such tenacity that he demanded I wear a helmet, then I attacked the neighbor’s trees. I made applesauce until I ran out of mouths to feed and canning jars to fill. Bursting with pride (and applesauce), I shuttled the remaining fruit back to Burlington, where it became the star of a dessert for the season’s first potluck.

Upon arriving at the event, I unveiled my creation and placed it among the other dishes. It accompanied…

…three apple pies. And nothing else.

The potluck’s four guests ate only apple desserts. In true Burlington spirit, someone arrived with a quinoa dish, but the damage was done. I was sick of apples.

But like a true naturalist, when I’m sad, I look to botany for comfort. I harkened back to a time when fruit was a buffet of discovery, not a monoculture of boredom. And I remembered this:

An apple, right-side-up

From a botanist’s perspective, I had been looking at the apple upside-down. Read More

Projectile Cucumbers

By Laura Yayac

wild-cucumberThe orbs dangle, pale green with darker stripes, like adorable baby watermelons on a vine of curls. Each one rests under its own leaf awning. Get closer, though, and you’ll see that this is no ordinary miniature fruit. Covered in spikes and ready to impale, it is at once magical and ominous. And that’s not the last of its tricks.

My encounter with the wild cucumber (Echinocystis lobata), a cousin of the ordinary garden variety, released my inner nature nerd. Are the wild cucumber fruits edible? If many plants rely on animals to eat their fruit and disperse the seeds, why the thorns on this fruit? How else would the seeds spread? I watched the crazy fruit over several weeks as it opened and split at the bottom – what triggered that process?

The answers were fittingly stellar for such a spectacular fruit. Read More

Hobblebush on Fire

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By Bryan Pfeiffer

An entire season of fall foliage flares from a single plant. Find your fireworks on Hobblebush (Viburnum alnifolium). This understory gem may be the perfect shrub. It adds food and habitat diversity – for nesting birds and other wildlife – beneath forest canopy. And its blooms play a crafty game of deception each spring. Read More

The Forecast Calls for Snowberries

snowberry3Now awaiting a frolic through your senses is one of nature’s most delightful candies, a reward so discreet that you probably pass it by during walks on life’s long, green path. When you are next high on some mountain trail, in dense coniferous woods, or near a spruce bog, find an elegant vine with tiny, waxy leaves. Drop to your knees because here is your low-hanging fruit: a sweet wintergreen explosion known as Creeping Snowberry.

No wild food is more enchanting. Creeping Snowberry (Gaultheria hispidula), a northern and boreal member of the heath family (Ericaceae), dispenses its little white gifts in August and September. Although I’m reluctant to mention them in the same sentence, Creeping Snowberry fruits resemble Tic Tac® candies. But beyond their size and shape, there is no comparison. Not even close. Willy Wonka couldn’t have designed a more intoxicating experience. Read More

Fir Waves

Fir_SmallBy Gus Goodwin

I suspect there is a positive correlation between one’s appreciation for fir waves and one’s distance from them.  From a distance, fir waves etch a pleasing pattern on the landscape, pose interesting ecological questions, and remind us that turmoil can be a form of stability.  Up close, they inflict scrapes and puncture wounds, incite expletives, and remind us to plan the next vacation to California, where the mountains have no trees (and it hardly ever rains).

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