Archive for the 'Trees' Category

Apr 18 2017

A Busy Week For Trees

Sugar maple flowers, 15 April 2017, Schenley Park (photo by Kate St. John)

Sugar maple flowers (wind pollinated), 15 April 2017, Schenley Park (photo by Kate St. John)

Are you sneezing yet?

It’s a busy week for trees in southwestern Pennsylvania as they open flowers and unfurl new leaves.

Redbud flowers fully open, 15 April 2017 (photo by Kate St. John)

Redbud flowers fully open (insect pollinated), 15 April 2017 (photo by Kate St. John)

 

In Schenley Park the trees are flowering everywhere, from insect pollinated redbuds (pink above) to wind pollinated sugar maples (yellow at top) and hophornbeams (below).

Hophornbeam catkins, 15 April 2017 (photo by Kate St. John)

Hophornbeam catkins (wind pollinated) 15 April 2017 (photo by Kate St. John)

 

Last weekend it was so dry that pollen coated my car and made my throat and eyes itch … and this was before the oaks had bloomed!  (Pollen note: Both oaks and pines are wind pollinated. Southwestern PA has an oak-hickory forest with few pines.)

Other busy trees include the bursting buds of hawthorns and hickories.  …

Hawthorn buds bursting, 15 April 2017 (photo by Kate St. John)

Hawthorn buds bursting, 15 April 2017 (photo by Kate St. John)

Bitternut hickory bud is opening, 15 April 2017 (photo by Kate St. John)

Bitternut hickory bud is opening, 15 April 2017 (photo by Kate St. John)

… and new leaves on Ohio buckeyes.

Ohio buckeye shows off its leaves, 15 April 2017, Schenley Park (photo by Kate St. John)

Ohio buckeye shows off its leaves, 15 April 2017, Schenley Park (photo by Kate St. John)

 

The city is a heat island so Schenley Park’s trees are ahead of the surrounding area.  Our red oak buds burst yesterday so you can expect several busy weeks ahead for trees in southwestern Pennsylvania.

Are you sneezing yet?

 

(photos by Kate St. John)

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Apr 16 2017

To see the cherry hung with snow

Published by under Phenology,Trees

Blooming cherry trees, Paris (photo from Wikimedia Commons)

Blooming cherry trees, Paris (photo from Wikimedia Commons)

Spend time today to see spring’s beauty. A reminder from A. E. Housman.

 

Loveliest of trees

Loveliest of trees, the cherry now
Is hung with bloom along the bough,
And stands about the woodland ride
Wearing white for Eastertide.

Now, of my threescore years and ten,
Twenty will not come again,
And take from seventy springs a score,
It only leaves me fifty more.

And since to look at things in bloom
Fifty springs are little room,
About the woodlands I will go
To see the cherry hung with snow.

A. E. Housman

 

(poem: The Loveliest of Trees by A. E. Housman (1859-1936), #II  from “A Shropshire Lad
photo: from Wikimedia Commons. Click on the image to see the original)

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Apr 12 2017

White Lace Among Bare Trees

Published by under Phenology,Trees

Downy serviceberry, a.k.a. shadbush, barking Slopes, 9 Apr 2017 (photo by Kate St. John)

Downy serviceberry or shadbush, Barking Slopes, 9 Apr 2017 (photo by Kate St. John)

The ground has thawed, the shad are running, and across the hillsides there’s white lace among bare trees.

Downy serviceberry (Amelanchier arborea) is one of the first wild trees to bloom in eastern North America.  At 30 feet tall with smooth gray bark, it opens its curly white flowers in early spring.  The tree stands out against the gray backdrop of the hills in April but we don’t notice it in summer. The birds do, though, because its reddish-purple berries are a favorite food.

Serviceberries have a wealth of common names.  On the eastern seaboard they bloom when a special fish, the American shad (Alosa sapidissima), swims upstream to spawn.  In that region it’s called a shadbush.

Shadbush at the Allegheny River, also called Downy serviceberry, 9 Apr 2017 (photo by Kate St. John)

Shadbush at the Allegheny River (where there are no shad), 9 Apr 2017 (photo by Kate St. John)

In Appalachia the serviceberries bloom when the ground has thawed enough to bury the dead and hold a funeral service.  Where the word service is pronounced “sarvis,” it’s called a sarvisberry.

Though they’re members of the Rose family and have perfect flowers (containing both male and female parts) serviceberries can reproduce asexually and they hybridize freely, crossing and back crossing until it takes an expert to identify them.  Even then there are disagreements.  David Sibley’s Guide to Trees points out that the number of species has ranged from 3 to 25; pegged at 16 when the book was published.  Downy serviceberry is one of them.

In Schenley Park I was able to reach a low branch and photograph the flowers.  This specimen is a cultivated variety, recently planted, so I can’t identify it for sure.

Serviceberry closeup, Schenley Park, 10 Apr 2017 (photo by Kate St.John)

Serviceberry’s “perfect” flowers, Schenley Park, 10 Apr 2017 (photo by Kate St.John)

But it can show you why one species has the downy name.

Downy serviceberry refers to the soft hairs on the back of its young leaves.  The hairs disappear as the leaves get older.

Do you think this cultivated leaf is downy?

Serviceberry flowers and new leaves, closeup at Schenley Park, 10 Apr 2017 (photo by Kate St.John)

Serviceberry flowers and new leaves at Schenley Park, 10 Apr 2017 (photo by Kate St.John)

Maybe so.

 

(photos by Kate St. John)

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Apr 09 2017

Lacy Trees

Published by under Phenology,Trees

Sun shining through the lacy leaves of an elm tree, early April 2017 (photo by Kate St.John)

Sunshine through a lacy tree, early April 2017 (photo by Kate St.John)

For five months Pittsburgh’s trees are bare.  This month they look lacy.

In April the trees open their tiny flowers and leaves.  Sunlight falls through the branches and heats the ground, prompting woodland wildflowers to bloom.

Many trees are still in bud.  The redbuds look dark pink because their rosy flowers aren’t open yet.

Redbud buds along the stem (photo by Kate St.John)

Redbud flower buds along the stem (photo by Kate St.John)

In a few weeks the trees will be full of leaves.  Now’s the time to appreciate their lacy look.

 

(photo by Kate St. John)

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Apr 01 2017

Signs of Spring in Schenley Park

Star magnolia, bursting bud, 29 Mar 2017 (photo by Kate St. John)

Star magnolia, bursting bud, 29 Mar 2017 (photo by Kate St. John)

On Wednesday I found more signs of Spring in Schenley Park.

Above and below, a star magnolia near the Westinghouse Fountain showed off its fist-shaped buds that burst into wild petals.  Did you know these flowering trees are imported from Japan?

Star magnolia blossom in Schenley Park, 29 Mar 2017 (photo by Kate St. John)

Star magnolia blossom in Schenley Park, 29 Mar 2017 (photo by Kate St. John)

 

Below, northern spicebush (Lindera benzoin) opened its tiny yellow flowers.  You can identify this shrub by smell.  Just rub your fingernail against the twig’s bark and smell the spicy citrus scent.

Spicebush blooming, 29 Mar 2017 (photo by Kate St. John)

Spicebush blooming, 29 Mar 2017 (photo by Kate St. John)

 

Most native trees haven’t opened their buds but this oak is getting there.

Oak buds opening, 29 Mar 2017 (photo by Kate St. John)

Oak buds opening, 29 Mar 2017 (photo by Kate St. John)

These buds will distend their wind-pollinated flowers first, then open the leaves.  This timing gives the flowers full access to the wind without any leaves in the way.

 

p.s. The oak bud photo looks fake but it’s a trick of the bright sunlight that put shadows on the buds in the background.  No retouching required.

(photos by Kate St. John)

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Mar 25 2017

Face In A Twig

Published by under Trees

A face in a twig, Schenley Park, 23 March 2017 (photo by Kate St. John)

A face in a twig, Schenley Park, 23 March 2017 (photo by Kate St. John)

After more than a week of cold weather, the buds were not bursting in Schenley Park last Thursday as I walked around taking pictures of Spring.

Instead, I found this unopened bud that looks like a devil’s face.

It’s the bud of a black locust (Robinia pseudoacacia) a very common tree in southwestern Pennsylvania that tolerates pollution and thrives in the poor soil of old fields, disturbed woodlots and roadsides.

Though black locusts have devilish looking buds and twisted branches, they’re good trees to have around because they enrich the soil through nitrogen fixation.

Their roots have a symbiotic relationship with the Rhizobium bacteria. Rhizobium enters the root hairs, the plant makes tumor-like growths to surround it, then the bacteria takes in nitrogen and converts it into a form that fertilizes the plant.  Strange but true.

Look for these devilish twigs soon.  When the buds open they won’t look like faces anymore.

 

(photos by Kate St. John)

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Feb 25 2017

A Bad Month For Maple Syrup

Published by under Phenology,Trees

Maple trees with sugar pails (photo from Wikimedia Commons)

Maple trees with sugar pails (photo from Wikimedia Commons)

There’s snow in this picture but there hasn’t been snow in Pennsylvania’s Laurel Highlands for half of this month.

March is supposed to be the best month for tapping sugar maples to collect sap for maple syrup.  The sap runs best with daytime temperatures above freezing and nights below freezing.  When the nights don’t freeze the sap stops running and the season is over.

This year Somerset County’s maple season was hampered by bursts of extremely warm weather in January and summer-like temperatures this month.  The thermometer hasn’t dipped below freezing since February 17 and some days have been more than 20oF above normal.  Maple sugaring stopped before it should have reached its best.

This trend isn’t unique to southwestern Pennsylvania.  The maple syrup industry tracks what’s happening to maple farmers from Virginia to Maine. Since 1970 they’ve noticed that the seasons have become shorter and the sap is less sweet so it takes more sap to make the same amount of syrup.

No matter where you stand on climate change the people whose livelihoods depend on cold winters (maple sugar farmers and ski operators) can tell you this:  Whacky climate ruins their business.

Read more here in a 2014 article from the Allegheny Front.

 

(*) Today the weather is yo-yoing again.  Meyersdale, PA will dip below freezing tonight (25 Feb) for two nights, then run up again to a 48oF low on Tuesday 28 Feb.

(photo from Wikimedia Commons. Click on the image to see the original.)

UPDATE on 7 March 2017: Here’s more on this year’s maple sugar season from the Allegheny Front, WESA-FM.

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Feb 19 2017

The Walking Palm

Published by under Trees

Roots of the walking palm, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

Roots of the walking palm, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

Here’s a tree whose roots are taller than a man and are said to “walk” 20 meters a year(*).  Really?

The walking palm (Socratea exorrhiza) is native to Central and South America where its narrow trunk grows 50-80 feet tall with stilt roots up to eight feet high. The walking palms at Wilson Botanical Gardens, Costa Rica were so tall that I couldn’t get their tops in the viewfinder.

Walking palm trees, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

Walking palm trees, Wilson Botanical Garden, Costa Rica, 2 Feb 2017 (photo by Kate St. John)

The tree’s claim to fame, repeated by local guides and the BBC, is that it can “walk” more than 65 feet a year by throwing out new roots to one side, leaning toward the new roots and abandoning those on the trailing edge.

But this is not true.

Reality Check:  20 meters per year is 65.6 feet, the height of 6 story building.  At 5.5 feet per month it’s a distance that’s easy to see and hard to ignore. You would notice that the plant is not where you left it!

Scientists have measured over and over and the walking palm never walks.  But they are puzzled why it has enormous stilt roots.  It occurred to me that an old theory about the roots may have spawned the walking legend.

In 1980, John Bodley and Foley C. Benson proposed that the tree has stilts so it can recover when downed by another tree, as shown in the diagram below.

How the stilt roots of Socratea exhorriza allow it to right itself (Bodley, John; Foley C. Benson (March 1980) via Wikimedia Commons)

1980: How the stilt roots of Socratea exhorriza allow it to right itself (from a paper by John Bodley & Foley C. Benson, March 1980, via Wikimedia Commons)

Tree #4 took root from the crown that hit the ground.  Its distance from the old root system is the height of the old tree. The trees average 65 feet tall.  Hmmmm!

Other fallen trees can sprout roots, too, and later studies disputed Bodley & Benson’s theory, yet none have solved the underlying mystery.  Why does Socratea exorrhiza have such long stilts? No one knows for sure.

Meanwhile, at Wilson Botanical Gardens the walking palms stay rooted where the Wilsons planted them.  Otherwise they’d be half a mile away by now.

 

(*) Meters or centimeters? See the comments here!

(photos by Kate St. John. Diagram from Wikimedia Commons; click on the image to see the original)

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Jan 26 2017

Faster Than Expected

Emerald Ash Borer galleries in bark (photo by April Claus)

Emerald Ash Borer galleries in bark (photo by April Claus)

On Throw Back Thursday:

Back in January 2010 when I first learned about emerald ash borer, I thought we’d see a slow decline of ash trees in the Pittsburgh area.

Not so!  The bugs wiped out the ashes much faster than expected.  Within five years Schenley Park’s ash trees were dead except for the few treated with pesticides.

What did things look like as the invasion began?  Here’s a look back seven years.

Doomed

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Nov 19 2016

Burls

Published by under Trees

Burl on black locust trunk (photo by Kate St. John)

Burl on black locust trunk (photo by Kate St. John)

November’s a good month to get reacquainted with trees. After the leaves are gone unusual features stand out.  That’s how I noticed these burls.

Burls are dense growths of deformed-grain wood and failed buds found on tree trunks or roots.  They’re a tree’s stress reaction to virus, fungus, bacteria or injury.

The wood in burls is sometimes beautiful but very dense and hard to work with.  Some species create particularly beautiful burl wood.  My hunch is that these two do not.

Above, a black locust.  Below, a white oak.

Burl on white oak (photo by Kate St. John)

Burl on white oak (photo by Kate St. John)

Take time this month to look at trees.

 

(photos by Kate St. John)

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