Quaker Ladies in the field

We rarely ever take the time to look at the smallest things.  We, very understandably, ooh and ah over vast landscapes, priding ourselves on climbing a mountain for the view that extends to the increased horizon.  All too often we overlook the smaller horizons, those under our feet, those that the vast majority of life with eyes sees.  The nearby, the up close, the things easily flattened under our feet in our quest for the big, the far, the distant.

Right now the Houstonia caerulea are blooming.

Field of Houstonia caerulea

They are known to most of us as Bluets and to some as Quaker Ladies. They grow in small cluster on the edge of meadows and in rich woods on well drained soils that get filtered light or short periods of direct sun. The flowers are often less than a centimeter across.  Most of the time we briefly admire them from where we stand, glancing down at these delicate flowers barely standing above the moss, leaf-litter, or short grass.  From our height the blue can be a mere suggestion of color, dominated by white.  The bright yellow star-like centers are barely visible.

From a little closer more details become apparent, but this invloves lying on the ground, thus most of us rarely see these little gems up close.

Small clump of Houstonia caerulea

It’s worth doing so, they are very pretty.

With a hand lens more detail becomes evident.

Houstonia caerulea iPhone with hand-lens

The vast majority of life with eyes on earth is tiny.  Their view of the world is more like the last photo than the first.  What we barely notice is a deep, dense forest to other living things.  When I can, I like to explore the world from this perspective, it reminds me of where we stand in the wider cosmos.


Glaciers and Camel’s Hump

Glaciers, geology, and meteor impact craters have always fascinated me.

Right now I live in New England, a landscape that was recently, geologically speaking, glaciated.  It has been about 12,000 years since the large glaciers here melted, leaving nothing behind but water, exposed bedrock, and a rubble of loose stones of various size and mud made from pulverized stone.  Plants raced for the freed nutrients and the forest wandered north with them.

Now Vermont is thickly forested up to all but the highest peaks.  Despite this signs of that past glaciation are everywhere, from large landscape features to the fine scale distribution of plants across that landscape.

One of the most prominent glacial features is the mountain Camel’s Hump, which, though not tall, can appear to loom over Burlington despite being 20 miles away.

I think it’s the implacable power of a glacier that awes me.  Large glaciers are otherworldly in a way that is difficult to convey.  The best description I have heard was in southeast Alaska where the large ice-fields are said to be the home of  the dead.  I spent two months working with a small group of people on the ice and it was easy to see why people said that.

Camel’s Hump, the mountain in the distance is a little over 4000 feet tall.  That’s a bit less than a mile.  At the height of the last glaciation the ice was more than twice that thick, burying Camel’s Hump so completely that you would only be able to tell it was there by looking via radar, sonar, or gravity scans.  If you were there, you would be standing more than a mile above the mountain top looking at a flat white plain stretching past the horizon in all directions.

That vast depth of ice weighed an enormous amount and moved under its own weight, slowly flowing across the landscape.  Glaciers are continually melting and the streams refreeze elsewhere.  Some of this water finds its way to the bottom of the glacier and refreezes in cracks in the underlying bedrock the glacier has just scoured clean.

Water expands when it freezes and fragments of the bedrock were broken free and held, frozen into the bottom of the glacier.  These entrained rocks scour the bedrock, like a file on metal, wearing it way, grinding it up, and tearing it loose.  The shapes a glacier carves the land into are extremely characteristic and have their own specific names; col, cirque, esker, moraine, drumlin, chatter mark, arête, roche moutonnée, and many more.

The glaciers that covered the New England landscape were large and the features they left are correspondingly large.

Camel’s Hump is a textbook example of a large roche moutonnée.  Roche moutonnée are low, rounded humps of bedrock rock that are ground into their shape by the action of a glacier.  I assume roche moutonnée owe their name, “sheep rocks”, to French and Swiss sheep herders who would have spent a lot of time looking at these low, rounded rocks while thinking about sheep.

The shape of a roche moutonnée shows the direction of glacier flow, and from Camel’s Hump you can see that the ice flowed from the north to the south, from right to left in the photo above.

The northern surface has been ground to a shallow angle, while the south side is steep and jagged, where the glacier ripped cathedral sized chunks of rock loose.

There is a clear vegetation line on the mountain, hardwoods lower down, evergreens above.  In Vermont the vegetation line is due primarily to temperature, moisture, and elevation.  In areas more recently deprived of their glaciers the bands of vegetation climbing the slopes provide an accurate means of dating how long it has been since the glacier left.

Nothing in nature is random, the glaciers don’t just carve their way willy-nilly across the land, their actions are directed by the bedrock they are so eagerly tearing asunder.  Camel’s Hump was a mountain before the glaciers came, and the glacier could only modify what was there, not make something completely new.

Seen from the south side, where the freeze/thaw and continual motion of the glacier have exposed the mountain’s heart you can see the folded, pastry dough like layers of rock that make up Camel’s Hump and the Green Mountains.

The tree covered slope beneath the cliff is a a boulder field dropped in place as the glaciers melted, now colonized by spruce and moss.

Bryophyta, Ancient and Tough

An ancient creature is waking up.  These creatures are small in stature but extremely tough.  They have been around longer than plants, although we often lump all green sessile things together.  Mosses are different though.

They have neither roots, nor vascular tissue, the plant equivalent of our circularity system.  They anchor to the substrate with little hold-fasts, somewhat like those giant algae, sea-weeds, and they drink though diffusion and osmosis.  They do well in places that are rich in airborne moisture.

Another things mosses lack is flowers and the associated seeds.  Like ferns, club-mosses, horsetails, and fungi mosses reproduce by spores.  By the millions.  They invest in quantity over quality and don’t pack any food or protection for their offspring before they cast them to the wind.  The spores will only germinate under perfect conditions.  Orchid growers are familiar with this problem, as orchids try the seed equivalent of this strategy.  Their dispersal strategy is like colonizing the galaxy by putting people in zip-lock bags and flinging them out of the solar system in the hopes that one of them eventually hit an earth-like planet.

This time of year the capsules that held the spores look like fossilized wind-socks.

Mosses are incredibly tough and individual stems from a colony can be very long lived.  A common way of judging the age of stair-step moss is the count the feather-like branches on a stem.  Five and seven year old moss stems are common and there are other mosses much longer lived than that.  An established moss colony may been in place for thousands of years.  Especially colonies in cold environments.

In the northern hemisphere we tend to think of plants and animals going dormant in response to cold.  If you can prevent the water in your tissues from freezing the danger for plants becomes one of dehydration.

Mosses, as I have said, are tough.  And Ancient.  They have some tricks they have learned over the hundreds of millions of years they have been around.  They learned these tricks before the ancestors of most of the things we see around us evolved.  Dinosaurs are latecomers to the party by the standards of the mosses.

Mosses dry up.  In a way the lessons learned as a spore transfer to the adults.  Most of their water evaporates, and as it does so the moss tissues curl in predictable ways.  The pores through which they breath close. Mosses can wait a long time like that.  Some mosses are so good at surviving this way that they grow in deserts.

Air in cold environments often contains less moisture than desert air.  Vermont has been even dryer than usual and many of the fir-cap mosses are still tightly furled, waiting for water.  Many look like the dry spires in the picture above.

Others have found enough water to wake up.

Like sponges, moss colonies trap water and fine debris.  The debris falls to the ground in the suddenly still water and becomes a nutrient supply for the mosses once they rehydrate.  Much like flowers they open as their tissues fill with water.

The growing tip opens as it hydrates revealing a tight furl of nascent microphylls (moss and clubmoss leaves) tinged a rosy hue.  Cold is well and good for living slowly, but growth requires warmth and the tips of the moss are shaped like little parabolic reflectors.  They trap both water and the sun’s light.  The reddish color may help them adsorb the long-wave understory light once the forest above leafs out.

From now through summer the new spore capsules will ripen, and come fall and winter they will scatter their spores across the landscape to drift with the wind, flow with the water, and run across the snow.

Unlike the poor fellows in zip-lock bags hurtling between the stars, the mosses have stacked the odds a little for their offspring.

Where water splashes moss may grow.  Where wind dies and lets drop what it carries moss may grow.  Where snow is late to melt moss may grow.

NOTE: The three close-in photos were taken though a 10x hand-lens held to the front camera of an iPhone4.