Category Archives: Trees

A Wasp, An Oak, and Indelible Ink

Screenshot from Making Manuscripts: Oak Gall Ink (source video below from the British Library on YouTube)

12 November 2023

Nowadays it’s rare to write anything by hand unless it’s the size of a Post-It note. When we really want to say something we use keyboards and touch screens to generate digital text read on screens or, less often, on paper. Our writing equipment becomes obsolete so rapidly that our computers and cellphones are replaced within a decade. (Who among us is still using the same cellphone since 2013? Do we even remember what model it was?)

So consider this: Humans used the same writing tool, the same indelible ink, from the 5th to the 19th century. When applied to parchment, it is readable 1,700 years later. The ink is easy to make by hand from natural ingredients and is still used in calligraphy today. To make iron gall ink, the process starts with a wasp and an oak.

When a cynipid wasp lays an egg in a developing oak leaf bud, the hatched larva secretes a substance that makes the oak surround it with a gall. The wasp (Andricus kollari) and the oak marble gall below are from Europe but similar wasps and oak galls occur in North America(*).

The outer shell of the gall is rich in tannins whose presence protects the wasp from predation.

Oak marble gall on white oak forced by Andricus kollari (photo from Wikimedia Commons)

When crushed and soaked in water the galls’ tannins give color to the ink.

Oak marble galls on the twig, forced by Andricus kollari (photo from Wikimedia Commons)

Two more ingredients transform the ink for final use: Iron sulfate dissolved in water makes the ink black.

Iron sulfate crystals (photo from Wikimedia Commons)

Gum arabic dissolved in water makes the ink sticky enough to hold onto parchment or paper.

Gum arabic in lumps and powder (photo from Wikimedia Commons)

This video from the British Library shows how iron gall ink is made.

(video embedded from the British Library on YouTube)

Eventually we used paper instead of parchment, even for important documents, and iron gall ink fell out of favor because the acid in iron sulfate makes the paper disintegrate. To solve that problem we invented paper-friendly inks and then computers.

Iron gall ink has oxidized the cellulose, causing the paper to disintegrate (from Wikimedia Commons)

Medieval manuscript creation used natural products from animals, plants and minerals. See the process from parchment to ink to binding in this 6-minute video from the Getty Museum.

video embedded from the Getty Museum on YouTube

Read more at Making Ink From Oak Galls: Some History & Science.

(*) p.s. The amount of tannin varies by type of gall and the tree species the gall came from. Galls with the most tannin work best.

(credits are in the captions)

Seen This Week

Eastern screech-owl, Frick Park, 7 Nov 2023 (photo by Charity Kheshgi)

11 November 2023

Songbird migration is quiet now and birds, when they’re found, are in mixed species flocks.

On 7 November, Charity Kheshgi and I encountered agitated golden-crowned kinglets, tufted titmice and dark-eyed juncos but it took us a while to find what they were upset about. This red morph screech-owl was hiding above our heads in a small oak.

Golden-crowned kinglet, Frick Park, 7 Nov 2023 (photo by Charity Kheshgi)

An exception to the mixed species flocking rule is our “murder” of crows. My guess is that Pittsburgh’s winter crow flock is 90% American and 10% fish crows, but who can tell? They look alike.

In late afternoon crows stage in the trees in Shadyside and Squirrel Hill, then head west at sunset. 6,000 to 10,000 pass by my building on their way to the roost.

Crows staging in Squirrel Hill just before dusk, 10 Nov 2023 (photo by Stephen Tirone)

At sunset black birds in a darkened sky are impossible to photograph but it’s another story at sunrise. Click on the photo below for a closeup of crows in the brightening sky.

Sunrise with crows, 2 Nov 2023 (photo by Kate St. John)

Leaves littered the ground this week and the air was filled with the sound of leaf blowers. 🙁

Fallen red maple leaf, 7 Nov 2023 (photo by Kate St. John)

Most of the trees were bare in Schenley Park by Friday 10 November.

Bare tree touched by sun, Schenley Park, 3 Nov 2023 (photo by Kate St. John)
Most of the trees are bare, 10 Nov 2023 (photo by Kate St. John)

And finally, a reminder that the rut is still in progress and deer are crossing roads. This duo showed up at a Squirrel Hill polling place on Election Day at a place surrounded by roads. So watch out.

Deer at the polling place on Election Day, 7 Nov 2023 (photo by John via Mardi Isler)

(credits are in the captions)

Bitternuts, Butternuts

Bitternut hickory nuts (photo by Kate St. John)

8 November 2023

The Nutty Series: Bitternut Hickory & Butternut

Though their names differ by only one letter bitternuts and butternuts are not the same at all.

Bitternut hickory (Carya cordiformis) is one of the most common hickories in southwestern Pennsylvania and easy to identify by its slender sulfur-yellow buds.

Bitternut hickory buds, April 2022 (photo by Kate St. John)

Bitternuts are closely related to pecans and also share the hickory genus with shagbark hickories, pignuts and mockernuts. Unlike the pecan the bitternut tree is rarely cultivated.

The fruit is a very bitter nut, 2–3 cm (0.75 – 1.25 in) long with a green four-valved cover which splits off at maturity in the fall, and a hard, bony shell.

Wikipedia: Bitternut hickory

The “green four-valved cover” turns brown after the nut lies around for a while (see middle nut at top) and indeed the shell is hard and bony. I had to use a hammer to open this one and damaged the perfect nutmeat in the process. You’ll have to imagine it was shaped like a short squat pecan.

Bitternut hickory nut, opened (photo by Kate St . John)

I can tell you from taste-testing that the nut is bitter and astringent. Squirrels avoid these nuts though Wikipedia says that rabbits eat them.


Butternuts (Juglans cinerea), on the other hand, are prized because the nuts taste good.

Butternut in its soft furry husk, similar to a black walnut (photo by Kate St. John)

Butternuts are in the same genus as black walnuts and sometimes called “white walnuts.” The leaf arrangement is so similar that I didn’t realize that I was looking up at a butternut tree — to see warblers — until I saw the nuts on the ground.

Butternut bark and leaves (photo from Wikimedia Commons)

Notice how similar the husks are: butternut on the left, black walnut on the right below. The butternut husk is oblong and fuzzy.

In the husk: Butternut (oblong and fuzzy) next to black walnut (rather smooth) – photos by Kate St.John

As the husk deteriorates (at left) the lumpy nutshell is revealed.

Butternut husk and nut at various stages (photos by Kate St. John)

A cross section of the nut shows the rough exterior and nutmeat inside.

Cross section of butternut with nutmeat inside (photo from Wikimedia Commons)

The butternut’s natural range runs from Maine and southern Ontario to southeastern Missouri and is smaller than the bitternut hickory’s. While the bitternut thrives, the butternut is declining and listed as threatened in some U.S. states and endangered in Canada. Its biggest threat is a fatal disease, butternut canker, caused by a fungus imported with the Japanese walnut. Ironically butternuts are partly threatened by too-easy hybridization with Japanese walnut trees.

Like black walnuts, butternuts are shade intolerant and thrive only when they’re at the top of the canopy or in an open space. Now that I know what a butternut looks like, I’ll pay more attention.

(credits are in the captions)

Beechnuts

American beech nuts, Oct 2023 (photo by Kate St. John)

1 November 2023

The Nutty Series: American beech

If you find a small spiny capsule on the forest floor that opens to reveal two to three nuts (in this case two are nicely packed together) you’ve found beechnuts. Without even looking up you can be sure you’re near an American beech (Fagus grandifolia).

American beech fruit capsule with nuts, Oct 2023 (photo by Kate St. John)

The fruit [of Fagus grandifolia] is a triangle-shaped shell containing 2–3 nuts inside, but many of them do not fill in, especially on solitary trees. Beech nuts are sweet and nutritious, can be eaten raw by wildlife and humans, or can be cooked. They can also be roasted and ground into a coffee substitute.

Wikipedia account: American beech, Fagus grandifolia
American beech seed capsule with nuts inside, Oct 2023 (photo by Kate St. John)

Beechnuts can be eaten raw? Well, it’s complicated. Foraging Beech Nuts explains that it’s best to let the capsules dry out for 2-3 weeks and then cook the nuts because some people get throat irritation from the raw seed coating.

In Pittsburgh’s parks beechnuts can be hard to find because they are so popular with deer and squirrels. Looking for a beech without looking up? Here’s another clue.

Beech drops (Epifagus virginiana) are parasitic on beech tree roots so if you see these well camouflaged plants you are definitely near an American beech. Read about them at On The Beech.

Beech drops (photo by Scott Zona via Flickr Creative Commons license)

Looking up at American beech trees this month you’ll see brown beech leaves clinging to the branches.

American beech leaves, 15 Nov 2021 (photo by Kate St. John)

Its buds are distinctive: long, pointed and golden brown like its fall leaves.

American beech buds and autumn leaf (photo by Kate St. John)

The trunk has smooth gray bark.

Bark of American beech, Nov 2011 (photo by Kate St John)

And at the end of winter, small American beeches have pale, rattling leaves that make them stand out in the forest.

Forest with young beech tree in February (photo by Kate St. John)
Forest with young beech tree, February 2018 (photo by Kate St. John)

All the beechnuts will be eaten or hidden by the end of winter.

p.s. If you’re my age you probably remember Beech-Nut chewing gum. Were there beech nuts in it? No, that was the name of the company. The gum’s claim to fame was its peppery peppermint zing.

Whatever happened to the candy? The candy division of Beech-Nut went defunct in 1976. Read about the Beech-Nut company here.

(photos by Kate St. John except for the beech drops photo by Scott Zona via Flickr Creative Commons license)

Autumn Beauty in the Woods

Beautiful autumn in the woods, 26 Oct 2023 (photo by Kate St. John)

28 October 2023

The last full week of October brought beautiful weather and fall foliage to Southwestern Pennsylvania. Early mornings were chilly but warmed up quickly. Here are a few scenes from the week.

  • Frick Park is beautiful in early morning sunlight on 26 October. With Charity Kheshgi.
  • American beech leaves in Schenley Park show three color stages: green, yellow, brown.
  • Sugar maple leaf is red at SGL 203, Marshall Twp
  • The arching trunks of a mature Norway maple in Shadyside, City of Pittsburgh.
  • Fall colors reflecting on Lake Arthur at Moraine State Park.
  • Beautiful sunrise on 26 October. Three crows pass by on their way from the roost.
American beech changing color, Schenley Park, 21 Oct 2023 (photo by Kate St. John)
Sugar maple leaf, SGL 203, 22 Oct 2023 (photo by Kate St. John)
Norway maple in yellow, Shadyside, Pittsburgh, 23 Oct 2023 (photo by Kate St. John)
Fall foliage reflection at Moraine State Park, 24 Oct 2023 (photo by Kate St. John)

Golden yellow is a them from leaves to sky.

Sunrise with three crows, 26 Oct 2023 (photo by Kate St. John)

(photos by Kate St. John)

You Can Tell A Tree By Its Nuts

Red oak acorns on the branch, August 2023 (photo by Kate St. John)

25 October 2023

By late October leaves and nuts are underfoot and still falling. Red oak acorns that were green on the branch in August litter the footpaths and sidewalks now.

Red oak acorns on the ground, Sept 2020 (photo by Kate St. John)

Underneath black walnut trees it’s hard not to misstep on the yellow husked nuts. You may even be hit by a black walnut detached and dropped by a squirrel gathering nuts above you. Squirrels save time by crawling all over the tree and detaching lots of nuts. Then they scurry down to collect them. Ouch!

Black walnuts in the husk (photo from Wikimedia Commons)

Keep looking down and you may find unusual nuts and seeds like these.

Magnolia cucumber tree lea and seeds, Sept 2011 (photo by Kate St. John)

Even without leaves, you can identify the trees above you by knowing the nuts at your feet. This fall I’ll run a series on identifying nuts found in western Pennsylvania.

Meanwhile to kick it off …

Adam Haritan explains a few trees you can identify without even looking up in this 15-minute Learn Your Land video.

video from Learn Your Land on YouTube

(credits are in the captions)

Leaf Peeping and Patchy Frost Prediction

Bright red maple leaf near Phipps Conservatory, 16 October 2023 (photo by Kate St. John)

21 October 2023

Fall color’s peak in southwestern Pennsylvania used to be around the 12th of October but climate change has pushed it later, closer to the 21st, as you can see in the PA fall foliage prediction for 19-25 October.

PA fall color prediction for 19-25 Oct 2023 (map from PA DCNR)

This week I found bright leaves on red maple trees, at top, and yellow on buckeyes and hickories.

Schenley Park leaves are yellow and green on 16 October 2023 (photo by Kate St. John)
Yellow and orange maple leaves, Frick Park, 18 October 2023 (photo by Kate St. John)

Frick and Schenley are dominated by oaks whose color will peak in the next two weeks. Meanwhile their few red maples turned red from the top down and have lost their leaves in the same order. The maples are gorgeous up close but you can’t see them from a distance because the tops are bare.

The top of this red maple is almost bare, 16 October 2023 (photo by Kate St. John)

Tomorrow night the northwest wind will bring migrating birds overnight and patchy frost on Monday morning.

This is the week to go leaf peeping.

(credits are in the captions)

Why Does the Water Look Like Tea?

Tannin stained water in Miners River, Michigan (photo from Wikimedia Commons)

15 October 2023

“Some tea with your river, Sir?” asks the caption on the satellite photo below where Rupert Bay meets James Bay in Quebec, Canada. James Bay’s incoming tide is pushing Rupert Bay’s tea-colored water upstream.

“Some tea with your river, Sir?” James Bay tidal water meets tannin-stained Rupert Bay, Quebec (NASA satellite image from Wikimedia Commons)
Tea-colored water is good.

In woodland and wetland settings, tea-colored water indicates that natural plant and water processes are occurring.

Frequently, water in streams and rivers becomes tea-colored from naturally occurring tannins, a chemical found in many plants around the world. The tannins can leach out of plants and plant debris and into groundwater, lakes, rivers, and streams. Although they can make the water more acidic, it’s important to note, tannins are not harmful to fish and wildlife.

This process occurs in many waterways that run through wooded areas and wetlands with high levels of plant mass and organic matter. Because there is always water flowing through these areas, tannins leach out of plants into the water, making it appear tea-colored.

Mainelakes.org: Why is the Water Tea-colored?

Tannins leach from all kinds of plant debris, especially soaked bark, leaves and pine needles in the north woods. There are tannins in this magnified Woody Dicot Stem: Tannins in Early First Year Tilia. Its caption reads: “Many cells in the periderm, cortex and pith contain dark staining tannins.”

Woody Dicot Stem Tannins in Early First Year Tilia (photo from Wikimedia Commons)

Leaves made these tannin stains on pavement.

Leaf stains on concrete in Chermside (photo from Wikimedia Commons)

There are tea-colored creeks in northeastern Pennsylvania such as this one in Monroe County.

Tobyhanna Creek, Monroe County, PA (photo from Wikimedia Commons)

And there are some special lakes on Florida’s Panhandle coast where the tea-colored water flows into the Gulf of Mexico. This video describes the dune lakes of Walton County.

Tannins are OK to drink though they may not taste good. In fact, it’s the tannins in tea leaves that make the beverage tea-colored.

Orange water deposits are bad.

Bright orange deposits are bad, even when the water is clear. In western Pennsylvania the orange color comes from abandoned coal mine drainage. Here the outflow of a polluted culverted stream dumps into Chartiers Creek near Bridgeville. Yuk!

Inflow of abandoned mine drainage into Chartiers Creek near Bridgeville (photo by Kate St. John)

Blacklick Creek in Cambria County, PA is another example.

Blacklick Creek is orange from abandoned mine drainage, 2007 (photo by Kordite via Flickr Creative Commons license)

Don’t worry if the water is tea-colored.

Do worry if you see bright orange deposits. In western PA our orange creeks and streams are a case of Water Everywhere, But Not a Drop to Drink.

(credits are in the captions; click the links to see the originals)

p.s. GEOGRAPHY! Though far inland, James Bay is tidal because it is the southern tip of Hudson Bay which connects to the Atlantic Ocean. This watershed map shows Hudson Bay watershed in green. Note the tiny red circle I added for the location of Rupert Bay.

Primary drainage basins in Canada (map from Wikimedia Commons)

Fall Color in Early October

Invasive burning bush shows off its fall color, Moraine State Park, 9 Oct 2023 (photo by Kate St. John)

14 October 2023

In October Pennsylvania’s Department Conservation and Natural Resources produces a weekly Fall Color Report with photographic samples from around the state. They promise this week will be colorful in the Northern Tier but we’re only getting started in southwestern PA. The fall color exception is Somerset County where high elevation creates a cooler climate.

PA fall color prediction for 12-18 Oct 2023 (map from PA DCNR)

As you can see, Pittsburgh’s Schenley Park is still mostly green …

… though a few maples are changing color.

The reddest maples are quick to drop their leaves so the predominant colors are still green and yellow.

Some flowers and fruits add a splash of color.

But for really gorgeous red and orange yesterday’s sunrise was the best.

Sunrise in Pittsburgh on 13 October 2023 (photo by Kate St. John)

“Red sky at morn, sailors forewarn” came true with today’s all-day rain.

(photos by Kate St. John, map from PA DCNR with link in the caption)

Proof! Lanternflies Don’t Hurt PA Trees; Sticky Tape is Pointless, Bad

Sticky tape put on trees by an unknown Frick Park visitor, 19 Sept 2023 (photo by Michelle Kienholz)

20 September 2023

Six years ago, when spotted lanternflies (Lycorma delicatula) were a new plague in North America, no one knew if they would destroy Pennsylvania’s forests but scientists assumed the worst and warned accordingly. However, they also conducted long term studies of spotted lanternflies’ effect on Pennsylvania trees and agriculture. For PA trees there is happy news: Spotted lanternflies are not a danger to Pennsylvania forests. There’s no need to protect our trees from lanternflies because they are not hurting them.

Penn State subjected four species of trees to four years of spotted lanternfly super-infestation by surrounding the trees with mesh nets that kept hordes of lanternflies inside. Silver maple, weeping willow, and river birch were barely phased by the bugs and did quite well in the third year of the study. The bugs’ host plant, the invasive tree of heaven (Ailanthus altissima), did not grow during the plague.

A Penn State study had four types of trees in enclosures with spotted lanternflies inside to see how growth would be affected. credit: Kelli Hoover/WPSU (photo embedded from WPSU)

The study’s lead author, Kelli Hoover, concluded:

“If you have a vineyard and you have lanternflies on your grape vines, you should be very worried because they can kill grape vines,” Hoover said. “But if you’re a homeowner and you have large trees on your property and you have lanternflies on them, I don’t think you should worry about it.”

WPSU: Spotted lanternflies not a danger to forests, according to Penn State study

When scientists learn new information, even if it contradicts an earlier statement, they change their advice to match the reality.

Six years ago they thought the trees were in trouble and needed protection. Now they’ve proven that spotted lanternflies don’t hurt our trees.

Six years ago they suggested sticky tape to protect trees but quickly learned it’s a terrible idea because it kills beneficial insects and birds and immediately changed their advice: Do NOT use Sticky Tape; use Circle Traps instead.

Yesterday an unknown visitor to Frick Park put sticky tape on some trees. Here’s what one section killed: 12 spotted lanternflies, 25+ pollinators (yellowjackets), 70 warbler-food insects (tiny flying insects). More beneficial insects died than lanternflies. Needless to say the tape has already been removed. (Click here to see how sticky tape kills birds!)

Sticky tape deaths in Frick Park, 19 Sep 2023 (photo by Michelle Kienholz)

Sticky tape is bad and pointless. If you put it up, remove it.

Sticky tape on a red oak (photo by Kate St. John)

Learn more about the spotted lanternfly tree study at WPSU: Spotted lanternflies not a danger to forests, according to Penn State study

p.s. Are you still worried because you saw one or two bugs on a tree? Not a problem. In September spotted lanternflies climb any vertical object whether or not they intend to eat it: trees, utility poles, buildings. Here they are on the guy wire of a utility pole. Yes, they are creepy but they are not eating the utility pole.

video embedded from ViralHog on YouTube

(photos by Michelle Kienholz, Kate St. John and embedded from WPSU website)