Friday, January 25, 2013

Urban Botany: a plant grows in Bratislava

Botanizing in downtown Bratislava; courtesy D. Poelma.
Follow the character in black down the steps to near the bottom of the photo, just right of center.  Do you see the plant growing out of the concrete, among accumulated dead leaves and a cigarette butt?  This is one of the most widespread plants in the world, though it routinely ignores an important rule for evolutionary fitness.

The leaves reveal its identity.  It’s a dandelion, also known as telltime, clocks, blowball, piss-a-bed, amargón, Taraxacum officinale and many other names.
The name by which we in the USA know it best -- dandelion -- comes from the French dent-de-lion or lion’s tooth, perhaps referring to the pointed lobes of its leaves.  Or perhaps it's the resemblance of the yellow flowers to golden teeth of heraldic lions (Dana 1893), though when I consulted Wikipedia I found no such critters -- only red-tongued varieties.
Question:  how many flowers in this photo?  Answer:  hundreds (by Greg Hume).
As for all members of the aster or composite family, the dandelion's inflorescence (flower cluster) is a head with many small flowers, called florets.  Pull out and pull apart a floret and you will find it contains all it needs to be a flower, i.e. reproductive organs.  Each has a corolla (petals, modified into a tube and strap), stamens (male) and a pistil (female).
Cross section through dandelion head showing many florets.  Enlarged floret on right:  teeth at end of ligule (strap) are evolutionary remains of petals; male anthers and female stigmas emerge from tubular portion of corolla.  Modified from  Köhlers Medizinal-Pflanzen (1887).
Dandelion in fruit; modified from  Köhlers Medizinal-Pflanzen (1887).
The ovule in the ovary of each floret matures to become a seed in a small dry ribbed fruit topped with a parachute, ready to travel far and wide on the wind.  The flat flowering heads turn into round fluffy balls often called clocks -- the basis of another of the dandelion’s names:  telltime.  Hopefully there still are children that tell time by blowing seeds from a clock and counting the number that remain.  Sometimes seeds blown from a dandelion carry the thoughts of one smitten with love, messages to an absent sweetheart.
Fly away sweet thoughts!  Photo by Alex Valavanis
Dandelions are filled with beauty, like this exquisite pattern of parachutes.  From Dandelion Clock - the clock you never see turn by Kirstie of The Family Adventure Project; used with permission.
Budding botanists usually are taught early on of the importance of outcrossing in plants, and of the many mechanisms that have evolved to discourage self-pollination.  Plants that pollinate each other rather than themselves produce more vigorous offspring, more adaptive variation, greater chances that their lineage will live on.  Or so they say.  But no one told the dandelions.

Most dandelions are apomictic.  They produce seed asexually, without pollination and fertilization, and though deprived of the evolutionary advantages of sex, they do quite well. Puzzling?  Not so much anymore, for our thinking has changed.  Dandelion offspring might have the same DNA as their parent, but other kinds of inter-generational information can differ.  Turns out environmental- and stress-induced epigenetic variation can be inherited too (Verhoeven et al. 2010), and the trials and tribulations of a parent can be reflected in its offspring!  This reeks of Lamarkism, inheritance of acquired characteristics, which we were taught was wrong.  Guess that was wrong too.

Able to reproduce without pollination, adept at dispersal, prepared to colonize the tiniest bit of open habitat -- it’s no wonder dandelions have done so well.  And their growing season is long.  They are among the first flowers of spring and the last in fall.
A dandelion blooms on an otherwise flowerless hike in the Laramie Mountains in late October.
The common dandelion, Taraxacum officinale, is native to Eurasia but now is a global plant.  It grows in southern Africa, South America, New Zealand, Australia, India and North America, where it occurs in all states and provinces of the USA and Canada.  It probably was introduced to North America by early colonists, for dandelions were in wide use in Europe as food, wine and medicine.

Dandelions are still used today.  Leaves are collected for salads, though slightly bitter (hence the Spanish name, amargón); they are high in vitamins A and C, iron and calcium.  Dandelion wine is made from the flowers.  The root is medicinal -- a diuretic -- and is the reason behind another of the common names, piss-a-bed.

In spite of their brightness, beauty, benefits, symbolism and amazing adaptations, dandelions often are treated as weeds, unfortunately.  They are especially vilified as the curse of lawns (themselves a curse! ... and self-imposed).    
Can there ever be too many dandelions?  Photo by Meteor2017.
Who would not find a field filled with bright sunny dandelions delightful?  They are symbols of hope, love and childhood, the summer ahead and the vigor of life!  I always look forward to their reassuring emergence each spring.

Literature Cited

Dana, Mrs. William Starr.  1893.  How to know the wild flowers.  NY: Scribner.

Verhoeven, Koen J. F. et al.  2010.  Stress-induced DNA methylation changes and their heritability in asexual dandelions.  NEW PHYTOLOGIST 185: 1108-1118.  (PDF here)

Tuesday, January 22, 2013

On the Rocks -- my favorite field brew (AW#54)

Glacial Till is this month’s host of the Accretionary Wedge (#54) and the topic is:  On The Rocks: Geo-Brews and Geo-Cocktails.  GT explains that one doesn’t have to drink alcohol to participate, so I’m in.
From UWSO via FB; source unknown.
I drink an occasional beer during summer field work but it's not required.  And my taste would impress no one, though it was shared by one of the greatest violinists of all times, Jascha Heifetz.  Coffee, on the other hand, is essential.  Espresso is the brew of choice for field work and road trips.

  Images above and below from
My first encounter with espresso was during a field project eighteen years ago when I stopped in the town of Broadus (population ca 400), on the Powder River in southeast Montana.  It's the largest community for many miles and I suppose a regional hotspot for cultural advancement.  There was a large sign on the drive-in (restaurant) -- “ESPRESSO”.  I went in to get food and overheard a middle-aged gal in line ahead of me explain,
“It’s like a whole pot of coffee in one cup!”
So I ordered one.  I can’t say the beverage was memorable, but the concept was.
I found espresso in Broadus, Montana, which claims to be the “wavingest town in the west”...
do the poor citizens now have to wave at every car with out-of-county plates?
(You may need to refresh or click Will to get a wave.)

Over the years, I’ve perfected my camp espresso.  Here’s the recipe, optimized for first-thing-in-the-morning, makes one cup (somewhere in the world, people drink from cups small enough that this would make three).
camp stove (building a fire takes too long)
“3-cup” stove-top expresso maker (here a durable stainless-steel Bialetti)
espresso coffee, i.e. finely ground
canned evaporated milk, optional
~1/4 teaspoon powdered cardamom, optional (cardamom??!)
Pack filter with coffee, add cardamom if desired (more about this below).  On cold mornings, first boil water to fill and heat cup; cover to keep warm.  Brew espresso.  Add evaporated milk to taste.

Now about that cardamom ...
Cardamon pods, a Wikimedia photo by Luc Viatour.
Cardamom is highly-revered in many parts of the world, and has reigned as Queen of Spices for over a thousand years.  It is the distinctive ingredient in gahwa, a beverage thought to have originated with the Bedouins.  Recipes on the Web range from equal parts coffee and cardamon to predominantly coffee.  I prefer the latter, which is fortunate given how expensive this spice is!  Many recipes include sugar.  Not for me ... sweet coffee has never made sense.  On the other hand, a sweet snack goes well, like dates or figs.
Enjoying a cup of gahwa in cowboy country.  We’re more progressive than you might think.
Photo source.

Thursday, January 17, 2013

Wonder of the Week: what happened here?!

A mysteriously-transformed river.
I had no intention of writing three posts in a row featuring the Laramie River, but some amazing things have been going on there.  Three days ago it was cold enough for the first walk of the season on the frozen snow-covered surface (below).
Frozen river with thin blanket of snow.
That night it was very cold, -20º F (-29º C).  The next morning I intended to take a long walk downstream but when I got to the river I found ... no snow ... just smooth milky ice.  At the margins the ice was very thin, with water below.  How could this be?  The temperature had not been above 0º F for almost 30 hours.  Then another surprise -- about a quarter of a mile downstream a blanket of snow still covered the river, no more bare ice.  [You will just have to believe me.  It was too cold for photos, I had no camera.]

The next morning (with camera) I found the river had changed again, to milky green ice with large patches of hoar frost here and there.
Patch of hoar frost in distance.  Anchored stumps on right are habitat for fish.
Clear area on left is ice, not open water.
There were wonderful patterns and textures to photograph, especially the swirls.
What a mix -- lobes and swirls of clear ice, translucent ice, hoar frost-covered ice.
Lobe of smooth ice surrounded by ice with fine hoar frost.
A bit of symmetry.  This reflected forest is green, even in winter!
The next day the river was different again -- less green, maybe because the sun was out.
What a mystery!  Any ideas as to how the river surface was transformed?  It was too cold for the snow to melt -- maybe wind? (I don’t remember any), or sublimation?  And why was there still snow on the river downstream?

Lucky for me I called the right friend, who knew the answer -- flood!  Water moved over the frozen surface, melting snow, freezing to form milky ice.  The swirls were shallow flood fronts.  The first day, flooding had made it downstream only to where the snow blanket still covered the river (it's gone now).
These once were swirling lobes of shallow water flowing over ice, now frozen in place.
How the river “flooded” was another question.  Maybe an ice dam upstream broke.  Maybe freezing expanding ice forced water onto the surface.  What do you think?
Small shallow flood fronts along the river margin -- water forced out by freezing expanding ice?
I’ve written quite a few posts involving the Laramie River (aggregated here), probably just because it’s close to my house.  But it is a treasure!  It's a strip of riparian and wetland habitat that winds through an equally-interesting collection of past and present human industry -- the old WyoColo and modern-day Union Pacific railroads, a ranch supply warehouse, old packing sheds, a sawmill, the railroad tie plant that became a superfund site transformed into open space.  Interstate 80 is less than a quarter mile to the west and always audible.  But step off the paved path and most days you will discover something of interest.  Nature thrives even in the midst of Civilization.
Sparky suffers through yet another photo expedition along the Laramie River.

Monday, January 14, 2013

Minimalism, symmetry, silhouettes and textures

Crow on wire.
A few days ago I discovered Anne McKinnell Photography by way of a link to Anne’s post on symmetry, part of her Creativity Booster series.  Then I read them all.  Here’s a woman after my own heart -- for me boldness, simplicity, patterns and abstract views are fascinating, even mesmerizing.

With my new knowledge, I headed out yesterday morning in search of minimalism, symmetry, silhouettes and textures.  It’s been pretty cold lately, and the river is well-frozen and suitable for strolling.  It was -6º F (-21º C), but sunny and incredibly still.

“In photography, images with the most impact tend to have less in them.  They are only about one thing.”  Simple lines are something to try -- so I spent some time with lines of tracks on the river.  But the minimalist photos that I like most are more surprising -- for example an interesting object in an otherwise homogenous or monotonous landscape.  And scale matters.  Snow is about as homogenous as you can get, but these track takes up too much space.  Also, an expanse of snow this size is nothing terribly impressive.  Better a yak on a snow-covered plain miles in extent.
Susannah of Wanderin’ Weeta recently posted a great minimalist shot of shorebirds in fog, a horizontal band of bird-spots with a few dark lines thrown in, almost in the middle of a very gray scene. You should check it out.
Simple compositions of just a few colors or shapes, or just a few elements, qualify as minimalist too.  A wonderful collection of frost ferns had sprouted under the old railroad bridge overnight; I ducked and carefully walked under to investigate.  But I heard some eerie cracking sounds so I backed out and tried another place.  Here was an equally nice collection of fernlike stellar dendrites and intriguing minimalist views of the underside of the trestle.

Even before my recent explorations of photography, I “knew” that symmetry in photos was to be avoided, that there is a golden ratio for arranging things, ... etc.  But not always, explains Anne, with convincing examples.
Architecture and other human-manufactured objects are obvious subjects, but nature too provides objects arranged in symmetrical ways.  “One way to find symmetry in nature is to look for reflections” ... or shadows!
I was wandering through a stand of cottonwoods working on silhouettes (next topic) when the potential for symmetry hit me.  I spent the next ten minutes making portraits of trees and their shadows.

Anne discusses the appeal of silhouettes, including the specific attraction for me (though I wasn't conscious of it ‘til now).  There is an appealing element of mystery to them.  We see mainly shapes, much detail is missing.  Lighting, shape and color are key to making silhouette photos work, as she explains.

At this point, though the camera was doing just fine, my camera hand was getting pretty cold, so I didn’t experiment much.  I did put the Canon Powershot A720 IS (a point-and-shoot) in manual shutter speed (Tv) mode and ramped up the setting hoping to not be overwhelmed by sunlight.  What I didn’t realize until I downloaded the photos was that the black-and-white setting left over from a hike several months ago was somehow activated in Tv mode.  Fortunately it was to good effect.  I suppose black-and-white reduces those distracting details even more.
I thought I might capture a symmetrical view of the sun above the old chimney in the UP railroad yard
(click photo for a better view).
I want to mention that when I first read through the Powershot manual, I found it a little hard to believe that so many settings and manual modes would be useful in a point-and-shoot.  But I underestimated the camera.  They aren’t that hard to use and worth the time to learn ... fun too.

Turns out “textures” are something I’ve been into for a long time (I call them patterns).  A nice thing about textures is that they can be photogenic in the bright light of midday or midsummer.  Here again, Anne is a kindred spirit.  In the Textures post, she gives due attention to the incredible beauty of plants and rocks up close and in the abstract.
Scanned print of a palm frond; 1997.
I found texture in stacks of old palettes, on the way back to the house and warmth.
I think this website will be useful for a photographer like myself -- with some experience, lots of interest, and no real training.  For example, I found a clear and informative post on controlling depth-of-field, though I will have to wait for warmer weather to experiment.  I’m happily reading one of Anne's two free ebooks, 8 Types of Natural Light ..., and may buy the latest, 8 Ways to Accelerate your Photography.

Are my photos getting better?  Who knows ... judgement is so much a matter of taste and perspective and the mood of the day.  But more and more I realize that the pleasures photography adds to looking at the world around me are my main motivation for doing it.  Towards this end, Anne's website looks to be very helpful.
The old packing plant, Laramie, Wyoming.
Vacation memories are all the richer for having spent time capturing them in photos!
Texture in an ancient bristlecone pine; White Mountains, California.

Wednesday, January 9, 2013

First Expedition of 2013

Close encounters with a pygmy snow wolf ... oh my!!
As soon as project reports were done, I grabbed the camera and headed out.  Contrary to popular belief, Wyoming botanists do not need to hibernate in winter.  Sure enough, this was a fascinating and productive expedition.

The first photo stop was non-botanical.  I’m intrigued by unusual or puzzling views of common objects, interesting arrangements of shape and color, like this:
It’s one of the benches along the river.  In summer, a man sits here and reads while his old dog wanders around in the shallow water completely absorbed, searching for crawdads.

Then I found this set of shadows ...
... and another version, in a different place
They're cast by slats on the footbridge.  It used to be a railroad bridge, now it's part of the Greenbelt Trail.  In summer, a kingfisher sits on the telephone wire just upstream, watching and fishing.
Next to the bridge, I found the showy milkweed was still standing.  Six months ago, it was covered with large clusters of ornate pink flowers.
Showy milkweed (Asclepias speciosa); by vicki watkins.
After pollination and fertilization, the ovules became seeds, and the little ovaries grew into these big pods, four to five inches long.
Our word for the day is anemochory, meaning seed dispersal by wind.  Milkweed seeds are topped with plumes so they can travel far and wide on the Wyoming wind.
When the pods have dried out enough, they dehisce and cast their progeny to fate, leaving an empty shell behind, reminiscent of an empty bed in the room upstairs.

Now over the river and into the cattail marsh ... no muck and easily passable this time of year.  Cattails in winter look a lot like cattails in summer, except that stems and leaves are straw-colored instead of green.
Narrowleaf cattails (Typha angustifolia).
Here’s the tail of the cat, which botanists prefer to call an inflorescence (flower cluster), with many thousands of flowers -- male in the upper cluster, female below.  Obviously cattails don’t go for showy flowers.  Theirs are tiny, with just the bare essentials -- no petals, no sepals, only reproductive structures and some bristles.

Below:  male flowers with long anthers and bristles, and male inflorescence, long after pollen has been released.

(Illustrations by the author.)
Above:  female inflorescence, and a single flower composed of a stalked ovary and numerous bristles (only a few are shown), ready for anemochory.

Now down to the river’s edge.  Here are more plants, and they just recently sprouted even though it’s -10º F!  How is this possible?  These are specially-adapted ice ferns -- particularly nice ones this morning, with large fronds; some are almost an inch long.
But these white ferns can’t photosynthesize.  In fact, sunshine is their demise and they will die soon.  And of course I’m kidding ... these fernlike stellar dendrites really were created by Jack Frost early this morning while we were all still asleep.

It was at this point, engrossed in snow ferns, that we were approached by the dreaded pygmy snow wolf!  Fortunately, Sparky scared it off ... 

When I returned home, I found these guys smiling.  Why so cheery?
Frost on the back door window is finally starting to melt, and the little bears are happily dancing in the sunshine.

The Laramie River Greenbelt Trail tours the riparian / light industrial ecotone along the Laramie River in southeast Wyoming.