Wednesday, April 25, 2012

PATTERNS: A KEY TO NAMING THE TREES


People are always asking me: Jon Spruce, how would you define ‘nature’ using only one word?

One word?  That’s easy.  Patterns.  The one word is patterns.

If you said cycles, I wouldn’t kick you out of the cabin.  That’s an excellent word to describe nature but I can’t see nature's cycles in my lifetime and I certainly can’t see them tree-hunting on these city streets. 


When I stare into the shaman’s fire and think in terms of nature’s endless cycles, I see images of Pangaea dispersing into continents, India crashing into China, dinosaurs surviving as birds, ice ages melting into rainforests, magma rocks building sedimentary shelves, underwater volcanoes sprouting sandy islands, drought and rain burying fossils, a 2.5-inch cone that I can squeeze between my fingers growing into the California Bigtree we call Sequoia and, above it all, the milky cloud-cover spinning forever around our blue planet.  And moss.  Lots of moss.

I’ll stick with patterns.  When I’m out tree-hunting, I’m looking for patterns.  The patterns help me identify the tree.   

Maybe it’s the way the branches are growing – opposite or alternate?  Maybe it’s the pattern of leaf shapes and sizes.  It could be the bark or the fruit.  If I can recognize the pattern that the tree is growing into, then I got a good shot at putting that tree into a family or a group, one step closer to knowing its name.     

Patterns in trees.

I’ll show you what I mean.

SECOND MOON OF WABUN

We’ve passed our way into the second moon of spring, the Frogs Return Moon.  I’ve been looking but I haven’t seen one frog yet.   

According to the Medicine Men, they’re out there though, returning.  From where they were.  I don’t know.  I don’t know much about frogs.

I’ll look for them later.

For the time being, I’m re-sharpening my dendrology skills, thanks to leaves, the easiest and most common pattern used for tree identification.  Know your leaves and you’re more than half-way there to the name, but I’m also going to be using branches, bark and seeds.

DISTINCT TREE PRIMER

Here’s an easy one.

 

















This is the London planetree, or the sycamore.  The difference between the two is minute and, seeing how they are planted up and down Philadelphia, it’s pretty easy to find one.  It’s the one that's planted in rows along the boulevards and parkways, the one that stands like a statue on certain street corners.  Their size, their stature and their ubiquity make it very distinctive but the easiest pattern to recognize is their mottled, camouflage bark. 

That camouflage bark is one of the reasons why it’s such a great city tree.  It’s constantly exfoliating its outer bark. That’s good for their survival since the city’s grime and pollution don’t have a chance to infect its interior wood.

Good for us too since we get to enjoy that distinct pattern of green, brown and creamy bark.

Here’s another easy one, another popular street tree.


This is the ginkgo tree, one of the most interesting and fascinating trees out there.  Their leaves don’t grow on twigs like most trees.  Instead, they sprout from those stubby nodes. See that duck-foot leaf.  Those are actually needles webbed together.  This tree has been around since the dinosaurs and is one of the missing links between leaves like pine needles and leaves like oak trees.

Two easy ones to name.  Field guides will call these two trees “distinct” because they don’t look like other trees.  I mean, if you can’t name a sycamore or a ginkgo, then you’re definitely getting kicked out of the cabin.

The Norway maple can also be found everywhere in this city.  Even if you’re not tree-hunting, they’re still easy to find.  You've probably tripped over the buckling sidewalk where they grow.  They’re notorious sidewalk killers.


The Norway maple I found wasn’t as big as they can get, but it’s still unmistakable.  Look at that big leaf, as big as my hand, and that long, thin petiole.  If you’re ever unsure if it’s a Norway maple, then rip off a leaf from the petiole and squeeze.  That milky white sap?  Distinct pattern.

Want to see another distinct leaf?  Find a tulip poplar.  You won’t see another leaf like that.  It’s often described as a “cat’s head.”  This is one of the biggest, tallest, largest native hardwood trees on this Turtle Island we call North America.  I can’t wait for their flowers to appear, should only be a couple weeks away now.

Let’s go a little faster.

CATCH A TREE IN A GLIMPSE OF AN EYE

Once you get certain patterns down, identifying most trees won’t take a lot of time.

When I’m walking down a city street and I see a tree coming my way, I’ll try to look for its distinct characteristics right away and, normally, by the time it’s passing over me, I’ll see one or two patterns and get its name.

I’ll show you what I mean.

White pine.  Pinus strobus.  I see, right away, those big, horizontally straight branches growing in tiers up its trunk.  This is one of the most important lumber trees in the history of the world, the tree that built the famous English navy, the tree that launched a thousand ships.  If I’m ever unsure, I’ll just snag a needle cluster as it passes by.  Five needles to a cluster?  Hello, white pine. Distinct pattern.

 

Next? Pin oak in the front yard.



I don’t even need to look twice.  See those lower branches growing at a 45-degree angle towards the ground.  Distinct pattern.  The only other tree that might do that is the sweetgum, but that’s more of a pyramid shape and it has star-shaped leaves.  Nope, that’s definitely a pin oak.


What's this one?

This one is a little tricky.  It’s either a bald cypress or a dawn redwood.  Both have feather-like leaves, a conical growing pattern and that beautiful reddish bark that peels away in small strips.   If it was later in the year, I could look for cones.  Cones growing upright?  Bald cypress.  Cones hanging down on a stem?  Dawn redwood.

What's next?  There's a cherry.

 

















The flowers are gone by now but I notice its stocky trunk.  I see those deep, horizontal scars.  They’re called lenticels and I think they have something to do with its respiration but, along with that gray color, it’s another distinct pattern.  Cherry.

On the corner of 43rd Street and Chester Avenue, I spot a birch.  You want to know how?  Those dangling, golden flowers called catkins.  I’m sure there are other trees that grow catkins but my first guess is always birch and, this time, I was right.

 

















I’m pretty sure this is a sweet birch but, since it’s obviously been planted as part of a landscape, I can’t be too sure without really digging into the field guides.  It could be some ornamental, non-native birch like European weeping birch.

But look at this birch.   



















This one is on Jackson Street in South Philly.  You want to see a distinct pattern?  Check out that shaggy bark just peeling off the tree.  No, this isn’t the famous paper birch that was used to make the birchbark canoes.  This is river birch, popular for a short time as a street tree for the very same reason as the sycamore.  Peeling bark is a formidable pattern to fight against the city’s natural ozone of grime, exhaust, pollutants, urine and loud car radios.

MULTIPLE CHOICES FOR TREE NAMING

Even if I can’t name a tree out of the corner of my eye, it only takes a few questions about its patterns to get to a name.

The other day, I noticed this tree on the street.  It has pinnately-compound leaves.  I’ll explain.   


That’s technically one leaf.  It’s called a compound leaf because there’s more than one leaflet.  It’s called pinnate because the leaflets are growing along a single stalk.  Pinnately-compound.

This kind of leaf pattern always catches my eye.  Why?  Because this could be a hickory.  I’m always on the lookout for hickories in the city.

But one quick glimpse into its crown and I notice another pattern.  


Its branches and twigs are growing opposite.  Do you see it?  A small branch grows out of a larger branch and, exactly opposite of that, another small branch is growing.  Distinct pattern.  Only a few trees grow their leaves and branches in an opposite pattern: maples, dogwoods, paulownias, horse-chestnut, olives and ashes being the most common, and there are only two trees I know that are both opposite and pinnately-compound: ash or the box-elder maple.

This is an ash tree.  The bark on older ashes is another distinct pattern, those deep, diamond furrows.

The ash tree is another important lumber tree, specifically harvested for sports equipment, from everything to tennis racquets to hockey sticks to baseball bats.  It’s valued for its tremendous bounce-back and, for fans of big baseball, it’s treasured for that thrilling sound of the home run thwack.

One more.

This next one took a couple tries to find its pattern.  I’ve been noticing these kinds of trees more and more.  I didn’t know their names but there was something very fetching about them.


It was hard to snap a photo of this pattern, but the undersides of their leaves are so much lighter than their topsides.  And then, look at how tight and orderly they grow along the branches.  As you walk under its crown, with just a little bit of wind and sunshine, these leaves twinkle like raining coins.  It’s lovely and memorable. 


Now what's its name?

I originally thought it was basswood, but I’m not that familiar with that kind of tree.  Looking it up in my favorite field guide, I could tell by the illustrations that I was a little off.  The leaves of a basswood are lopsided.  The leaves that I was noticing were symmetrical, a little dimpled and heart-shaped, not lopsided and uneven. 

And there on the opposite page of the field guide, there it was.  Littleleaf linden.   Pretty sure.

 













This is a rewarding experience, to notice patterns in the living world.  This is especially true for trees.  Taken in one glance, there are many parts to a tree: its shape, its growth, its habitat, its leaves and branches, its colors and seeds and fruits and bark and who knows how many patterns there are underneath in that whole kingdom of roots happening out of sight?  It’s a daunting machine, with lots of moving parts, a tree.  The patterns are there though, if you know where to look and what to ask.

One more.  This one is in Clark Park in West Philly. See this thing growing crooked and lean into the high skies.  I know this tree already.  This is a Kentucky coffee-tree, an uncommon tree in these parts.  


This picture was taken now, during the beginning of the Frogs Return Moon, but I identified it two summers ago.  Its distinct pattern isn’t out yet but here’s a picture of it:


See that?  That is, botanically speaking, one leaf.  It’s bi-pinnately compound, one pattern beyond the ash tree’s leaf.  It’s a series of leaflets next to sub-leaflets, leaf-stalks growing out of leaf-stalks.  Yeah, not many trees have this many parts to a single leaf.  Kentucky coffee-tree.

Those large, complicated leaves won’t be out till the beginning of the summer, not until Corn-Planting Moon.

Corn-Planting time?  Only a few weeks away.  I got to find me some frogs before it's too late.  The Wheel tells me that they are out there, returning.



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