Archive for the 'Phenology' Category

May 23 2017

Fluff In The Air

Published by under Phenology,Plants

Cottonwood fluff on the ground (photo by Chris Evans, University of Illinois, Bugwood.org)

Cottonwood fluff on the ground (photo by Chris Evans, University of Illinois, Bugwood.org)

In late May, you’ll see white fluff in the air as you search the sky for birds.  It’s not dandelion fluff.  This is cottonwood season.

The eastern cottonwood (Populus deltoides) grows in open and riparian habitats from the Rockies to the southeastern coast. Western Pennsylvania is on the eastern edge of their range.

Range map of the eastern cottonwood (image from Wikimedia Commons)

Range map of the eastern cottonwood (image from Wikimedia Commons)

 

Cottonwoods are one of the fastest growing and largest trees in North America.  Reaching up to 130 feet tall the trunk can be more than five feet across.  The trees require bare soil and full sun to germinate so you usually see them out in the open, sometimes alone.

Eastern cottonwood (photo by Steven Katovich, USDA Forest Service, Bugwood.org)

Eastern cottonwood (photo by Steven Katovich, USDA Forest Service, Bugwood.org)

 

Their species name, deltoides, describes the leaf shape that looks a lot like aspens. Both trees are in the willow family.

Cottonwood leaves (photo by T. Davis Sydnor, The Ohio State University, Bugwood.org)

Cottonwood leaves (photo by T. Davis Sydnor, The Ohio State University, Bugwood.org)

 

In early spring cottonwoods sprout male and female catkins. The females are fertilized by wind-blown pollen and become drooping strings of seed capsules.  In May the capsules burst open to release thousands of tiny seeds, each one attached to a bit of “cotton” that carries it on the wind.  (The brown spots in this photo are seed capsule covers, not the seeds.)

Eastern cottonwood seeds, still on the branch (photo by Troy Evans, Great Smoky Mountains National Park, Bugwood.org)

Eastern cottonwood seeds, still on the branch (photo by Troy Evans, Great Smoky Mountains National Park, Bugwood.org)

 

The fluff breaks off and blows away but each tree is so prolific that in windless conditions, when the fluff falls straight to the ground, it looks like snow.

Do you want to see a lot of cottonwood fluff?  Drive north on Route 528 from the bridge over Moraine State Park‘s Lake Arthur. Eventually cottonwoods are on both sides of the road.

There’s fluff in the air there!

 

(photo credits:
fluff on the ground by Chris Evans, University of Illinois, Bugwood.org
range map from Wikimedia Commons; click on the image to see the original
clump of cottonwood trees by Steven Katovich, USDA Forest Service, Bugwood.org
cottonwood leaves by T. Davis Sydnor, The Ohio State University, Bugwood.org
cottonwood seeds on the branch by Troy Evans, Great Smoky Mountains National Park, Bugwood.org
)

5 responses so far

May 21 2017

Jack In The Pulpit

Published by under Phenology,Plants

Jack in the pulpit, Schenley Park (photo by Kate St. John)

Jack in the pulpit, Schenley Park (photo by Kate St. John)

Jack in the Pulpit (Arisaema triphyllum) has been blooming for about two weeks in western Pennsylvania.  As the forest floor greens up you might not notice this unusual flower.

Here’s a whimsical look at Jack’s odd characteristics.  Sometimes he is “Jill.”

Jack Explains Himself

 

No responses yet

May 19 2017

Apples in May

Mayapple flower turning into a May Apple (photo by Kate St. John)

Mayapple flower turning into an apple in May (photo by Kate St. John)

I’m taking a break from peregrines today.   Here’s a plant.    🙂

In Schenley Park, mayapples (Podophyllum peltatum) bloom in April and fruit in May. The plants must have two leaves to produce a flower because the flower stalk grows from the Y between the leaves.

Here’s what they look like when they bloom.

Mayapple in flower with twin leaves (photo from Wikimedia Commons)

Mayapple in flower with twin leaves (photo from Wikimedia Commons)

The fertilized flower transitions from flower to apple in May, as shown in the photo at top.

You can eat a mayapple when it’s ripe but Be Careful!  The entire plant is poisonous and the apple is only edible when ripe!  Find out more and see a mayapple sliced open in this vintage article from 2011.

Eating Mayapples

 

 

(top photo by Kate St. John. Blooming photo from Wikimedia Commons; click on the image to see the original)

2 responses so far

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)

3 responses so far

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)

3 responses so far

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)

One response so far

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)

2 responses so far

Apr 07 2017

April Showers Bring …

Published by under Phenology,Plants

Yellow corydalis at Cedar Creek Park, 6 April 2017 (photo by Kate St. John)

Yellow corydalis at Cedar Creek Park, 6 April 2017 (photo by Kate St. John)

The weather was beautiful on Wednesday when my friends and I found hopeful signs of spring at Cedar Creek Park in Westmoreland County.  There were two Best Birds (yellow-throated warbler, Louisiana waterthrush) and many April flowers including hepatica, Virginia bluebells, twinleaf, bloodroot, harbinger of spring, and …

Yellow corydalis (Corydalis flavula) is a native annual in the Poppy family. Its small flower, 1/4″ long, has an unusual puckered shape.

The most common spring beauty in our area, Claytonia virginica, has thin grass-like leaves.  Carolina spring beauty (Claytonia caroliniana) has oval leaves and deeper pink flowers.

Carolina spring beauty at Cedar Creek Park, 6 Apr 2017 (photo by Kate St. John)

Carolina spring beauty at Cedar Creek Park, 6 Apr 2017 (photo by Kate St. John)

 

Wild blue phlox (Phlox divaricata) was on the verge of blooming last Wednesday.  Here’s one stunning flower.

Wild blue phlox at Cedar Creek Park, 6 Apr 2017 (photo by Kate St. John)

Wild blue phlox at Cedar Creek Park, 6 Apr 2017 (photo by Kate St. John)

But this morning all is changed.  It rained all day yesterday and now we have gusty winds and snow flurries.  🙁

Thursday’s April showers closed the flowers.

 

(photos by Kate St. John)

One response so far

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)

No responses yet

Mar 28 2017

Now Blooming at Raccoon Creek

Published by under Phenology,Plants

Harbinger of spring, 26 Mar 2017, Raccoon Wildflower Reserve (photo by Kate St.John)

Harbinger of spring, 26 Mar 2017, Raccoon Wildflower Reserve (photo by Kate St.John)

Last Sunday, 26 March 2017, I visited Raccoon Creek State Park’s Wildflower Reserve to see the newest flowers.

The woods were brown and the sky was gray so I had to look closely to find small signs of spring.

Raccoon Creek at the Wildflower Reserve, 26 Mar 2017 (photo by Kate St. John)

Raccoon Creek at the Wildflower Reserve, 26 Mar 2017 (photo by Kate St. John)

(Winter floods scraped the creekside vegetation. Click on the creek photo above to see.)

 

Harbinger of spring (Erigenia bulbosa) was opening its tiny salt-and-pepper flowers, shown at top and below.

Harbinger of spring, just opening, 26 Mar 2017 (photo by Kate St. John)

Harbinger of spring, just opening, 26 Mar 2017 (photo by Kate St. John)

 

It was fun to find blue flowers in the grass:  corn speedwell (Veronica arvensis), a non-native.  Our earliest spring natives aren’t this bright.

Speedwell blooming in the grass, 26 Mar 2017, Raccoon Creek State Park (photo by Kate St. John)

Speedwell blooming in the grass, 26 Mar 2017, Raccoon Creek State Park (photo by Kate St. John)

 

Snow trillium (Trillium nivale) was past its prime.

Snow trillium past its prime, 26 Mar 2017, Raccoon Wildflower Reserve (photo by Kate St. John)

Snow trillium past its prime, 26 Mar 2017, Raccoon Wildflower Reserve (photo by Kate St. John)

 

Spring beauty (Claytonia virginica) was blooming everywhere.  This one is surrounded by garlic mustard. 🙁

Spring beauty, 26 Mar 2017 (photo by Kate St. John)

Spring beauty, 26 Mar 2017 (photo by Kate St. John)

 

Round-lobed hepatica (Hepatica nobilis) bloomed among old oak leaves.

Round-lobed hepatica, 26 Mar 2017 (photo by Kate St. John)

Round-lobed hepatica, 26 Mar 2017 (photo by Kate St. John)

 

And cutleaf toothwort (Cardamine concatenata) was in bud on the south facing Jennings Trail near Shafers Rock.  I’m sure it will bloom this week.

Cutleaf toothwort, 26 Mar 2017, Raccoon Wildflower Reserve (photo by Kate St.John)

Cutleaf toothwort, 26 Mar 2017, Raccoon Wildflower Reserve (photo by Kate St.John)

 

(photos by Kate St. John)

One response so far

Next »