Category Archives: Plants & Fungi

plants & fungi

St. Patrick’s Lucky Shamrock is Harder to Find

Four leaf clover among a patch of Trifolium repens (photo from Wikimedia Commons)

17 March 2025

Happy St. Patrick’s Day!

St. Patrick’s and Ireland’s shamrock symbol is a leaf cluster of either lesser clover or white clover. We don’t see much lesser clover (Trifolium dubium) in the U.S. but we used to have lots of white clover. When I was a child our lawns were a mixture of grass and white clover (Trifolium repens).

House sparrow on a lawn of grass and white clover (photo from Wikimedia Commons)

The mixture worked well because clover sets nitrogen in its roots and naturally fertilizes the grass. As kids we used to search for lucky 4-leaf clovers in the yard.

Three 4-leaf clovers (photo from Wikimedia Commons)

But times changed. People didn’t want weeds in the lawn and the easiest way to remove them was to spread weed killer that targeted broadleaf plants. Clover is a broadleaf so it died and fertilizer had to be added to the chemical mix.

These neighboring lawns in New Jersey show both types of lawn treatments. At top is a chemically treated lawn without broadleaf plants. At bottom is an old fashioned grass-and-clover mix. If you can’t see the dividing line, click on the photo to see the divide.

Neighboring lawns in New Jersey: herbicide vs clover (photo from Wikimedia Commons)

Chances are you’ll have to search for lucky 4-leaf clovers in a photo instead of on the lawn. How many are in this photo? (Click on it to see a larger version.)

How many 4-leaf clovers in this patch? (photo from Wikimedia Commons)

p.s. False Shamrock: The “shamrock” plant often sold around St. Patrick’s Day is not related to clover. “False shamrock” or “purple shamrock” (Oxalis triangularis) is native to Brazil.

False or purple shamrock, Oxalis triangularis (photo from Wikimedia Commons)

The Crocus Report

Woodland crocuses blooming in the lawn on Neville Street, 4 March 2025 (photo by Kate St. John)

5 March 2025

The crocuses are blooming!

But of course they are. In yesterday’s sunny and unseasonably warm 67°F the woodland crocuses (Crocus tommasinianus) on Neville Street were in full bloom. I say “were” because today’s rain, clouds and wind will probably keep them closed.

The crocuses dotted the lawn, above, and opened their petals to the sun.

Woodland crocus blooming in the lawn on Neville Street, 4 March 2025 (photo by Kate St. John)

Honeybees came to take a sip.

Bee visits blooming crocuses in the lawn on Neville Street, 4 March 2025 (photo by Kate St. John)

Now that they’ve opened, how does this year’s crocus bloom date compare to those in the past? Is it later than usual because we had such a cold winter?

Surprisingly, this year is on the early end of the spectrum, based on my record of Crocus First-Bloom Dates in Pittsburgh’s East End since 2009.

Plotted on the calendar it’s easy to see that the dates cluster and the outliers are early, not late. Repeated dates are circled twice. Interestingly, the dates in February become earlier each time they occur.

2025 calendar from timeanddate.com showing Crocus blooming dates in Pittsburgh’s East End, 2009-2025

And the crocuses are not alone. Snowdrops are blooming too.

Snowdrops in bloom, 4 March 2025 (photo by Kate St. John)

Then and Now: Comparing Spring This Week

Honeysuckle leaves in a Too Early Spring, 20 Feb 2018 (photo by Kate St. John)

20 February 2025

Yesterday I looked back seven years and found photos of honeysuckle leafing out! Obviously we’re having a very different February than we did in 2018 when it was hotter than normal.

How does this year’s Spring status compare to years past? Here are a few photos for comparison.

Maple tree flowers: 2023 vs 2025

Only two years ago the maple trees had started blooming by now. This week the buds are still slammed shut.

Maple flowers blooming on 17 Feb 2023 (photo by Kate St. John)
Maple buds slammed shut on 18 Feb 2025 (photo by Kate St. John)
The Tulip Garden: 2024 vs 2025

Last year the tulip leaves were standing tall. This year they emerged and stopped.

Tulip leaves standing tall a year ago, 7 Feb 2024 (photo by Kate St. John)
Tulip leaves emerged and paused, 18 Feb 2025 (photo by Kate St. John)
The Crocus Lawn: 2023 vs 2025

Two years ago this lawn on Neville Street was carpeted in blooming crocuses. This week it’s covered in snow.

The crocus lawn on 21 Feb 2023 (photo by Kate St. John)

Yesterday that lawn looked like this.

The crocus lawn on 18 Feb 2025 (photo by Kate St. John)

And here’s an interesting juxtaposition …

High water comes and goes: 2018 vs 2025

The Monongahela River at Duck Hollow flooded the parking lot seven years ago. This month the highest reach was well below the parking lot.

Monongahela River flood at Duck Hollow, 17 Feb 2018 (photo by John English)
Monongahela River highest water in February 2025 (so far), 3 Feb 2025 (photo by Kate St. John)

I was surprised to learn that January 2025 was Earth’s hottest January on record considering that it snowed in New Orleans and Pittsburgh had -8°F.

This map shows why we’re confused by this news. While most of the world and everything north of us was extra hot, the Continental US was unusually cold in January 2025.

January 2025 global land and ocean temperature departure from average base period 1990-2020 (map from NOAA)

Twirling Kudzu Like Spaghetti

Kudzu draping trees in Atlanta (photo from Wikimedia Commons)

31 January 2025

If you’ve ever been to Atlanta you’ve seen areas like the one pictured above where invasive kudzu is draped over everything. You can see why it’s called “The vine that ate the South.”

Kudzu was introduced to the Southeast U.S. back in 1883 and given a healthy head start on its way to invasion.

The vine was widely marketed in the Southeast as an ornamental plant, … as a high-protein content cattle fodder and as a cover plant to prevent soil erosion.

By 1946, it was estimated that 3,000,000 acres of kudzu had been planted [in the U.S].

Wikipedia: Kudzu in the United States, emphasis added

Planted!

Now that the genii is out of the bottle, how do we get rid of it? Good question.

The video below shows an interesting technique that is not enough to eradicate kudzu but is very satisfying to watch.

The “business” end of the equipment is a claw or grabber attached to a Tiltrotator on an excavator. It twirls the kudzu like spaghetti.

video embedded from TheRegrowthProject on YouTube

His Winter Cache Bloomed 32,000 Years Later

Arctic ground squirrel with stuffed cheeks, Russia (photo from Wikimedia Commons)

17 December 2024. Old news from 2012 with a recent update.

Food is scarce in the arctic during winter and early spring, so arctic ground squirrels (Urocitellus parryii) fatten up for hibernation and cache food for later use.

Arctic ground squirrel in Russia, eating flowers and seeds (photo from Wikimedia Commons)

When they wake up in April they have seeds in their cache to fall back on before the arctic blooms.

32,000 years ago, during the Ice Age, a ground squirrel stored food in his midden that he never ate. If everything had remained frozen no one would have known about his cache, but climate change is melting glaciers and ancient ice. Eventually the squirrel’s cache was exposed.

Melting glacier (photo from Wikimedia Commons)

Twelve years ago Russian scientists collected the squirrel’s cache and found intact seeds within so they cultivated them in the lab. The fertile seeds grew into a 32,000 year old plant, the oldest on Earth.

After they published their findings they continued their research and cultivated more seeds, identifying them as Silene linnaeana in 2021. This is the same genus as bladder campion.

screenshot from Molecular taxonomic identification of a Silene plant regenerated
from Late Pleistocene fruit material at researchgate.net

Here’s a sample blooming in the Sahka Republic of Russia in June 2023 (from iNaturalist).

Silene linnaeana (photo from iNaturalist.lu)

What will happen to this squirrel’s cache 32,000 years from now?

Arctic ground squirrel (photo from Wikimedia Commons)

Seen This Week: Color + a Major Lunar Standstill

Orange! at Phipps Conservatory, 12 Dec 2024 (photo by Kate St. John)

14 December 2024

Color! Avoiding this week’s coldest weather, Charity Kheshgi and I visited Phipps Conservatory during their annual Holiday Magic flower show. This time I was captivated by summer colors. Orange! Yellow!

Yellow! at Phipps Conservatory, 12 Dec 2024 (photo by Kate St. John)

A Major Lunar Standstill is coming up tomorrow.

The Full Moon on December 15, 2024, will rise and set at its most extreme northerly points on the horizon—the result of a once-every-18.6 years “major lunar standstill.”

Time And Date: Look Out for December’s Extreme Full Moon

How odd that just days before the winter solstice, when the sun stands still and rises and sets at its southernmost point, the moon is standing still at its northernmost point.

Watch for it tomorrow. Here’s the moon this morning with Jupiter to its left.

Jupiter and the Moon on their way to setting in the west, 14 Dec 2024 (photo by Kate St. John)

Seen This Week: Confused Flowers

Rose blooming in November, 23 Nov 2024 (photo by Kate St. John)

30 November 2024

Even though it’s November and getting colder and darker by the day, I found some confused flowers this week. Imported trees and plants that should be dormant were in bloom.

A rose, above, and an ornamental cherry tree were beautiful in the rain.

Ornamental cherry tree blooming in November, 23 Nov 2024 (photo by Kate St. John)

Moth mullein was battered but blooming on an almost sunny day.

Battered but blooming, moth mullein in November, 23 Nov 2024 (photo by Kate St. John)

Northern magnolia buds were swelling in anticipation of spring … even though it was late November.

Fat buds on northern magnolia, 27 Nov 2024 (photo by Kate St. John)

Alas, these flowers will be no match for this week’s (finally normal) freezing temperatures.

Seen This Week: Fruits and Seeds

“Monkey balls” = fruit of osage orange tree, Schenley Park, 20 Nov 2024 (photo by Kate St. John)

23 November 2024

Now that the leaves have fallen fruits and seeds are prominent in the landscape.

Osage orange (Maclura pomifera) trees have prolific fruit this fall but nothing eats the “monkey balls” so they just lay on the ground to rot. If you crack one open it has sticky latex inside. Who would eat this fruit? The answer is in the video at the end!

The fruiting body of a shaggy mane mushroom (Coprinus comatus) poked up among the leaf litter near Five Points at Moraine State Park.

Fruiting body of Shaggy Mane mushroom, Moraine State Park near Five Points, 18 Nov 2024 (photo by Kate St. John)

Red fruits of oriental bittersweet (Celastrus orbiculatus) are a favorite food of migrating American robin, protected by a hard yellow-orange skin that pops off in sections. It looks like a squirrel gnawed off this branch and lost his meal.

Fruit of oriental bittersweet, 18 Nov 2024 (photo by Kate St. John)

Late boneset has gone to seed in Schenley Park.

Late boneset seeds surrounded by fluff, Schenley Park, 20 Nov 2024 (photo by Kate St. John)

Just a few trees still have leaves. I found this colorful sweetgum along a sidewalk at CMU. Someone ripped a piece off the yellow leaf.

Colorful leaves on sweetgum, 20 Nov 2024 (photo by Kate St. John)

BONUS! Who eats monkey balls?

video embedded from Ghosts of Evolution on YouTube

Some Plants Are Simply Female

Female spicebush with berries, 25 Sept 2017 (photo by Kate St. John)

21 November 2024

In the garden we often grow “perfect” flowers such as roses, lilies and tulips with male and female parts in every flower. However, many woody shrubs and trees have single sex flowers. Some species grow both sexes on the same tree, others have only one sex on an entire plant. And so, some plants are simply female.

Compare this “perfect” bisexual flower diagram …

Diagram of a flower with both female and male parts (image from Wikimedia Commons)

… to single sex flowers.

Diagrams of female and male flowers (altered from the perfect flower on Wikimedia Commons)

Monoecious species have both flower sexes on the same plant. Examples include hickory and pecan trees, cucumbers and pumpkins, cherries, common grape vine and corn (maize).

Dioecious plants produce only male or female flowers on individual plants and only the female plants produce fruit. Examples include gingkos (stinky fruit from female trees!) …

Fruit and fallen leaves from a female gingko tree (photo from Wikimedia Commons)

… and holly trees –> You can’t get holly berries if you have only one tree.

Holly leaves and berries (photo from Wikimedia Commons)

Knowing this, you can sex dioecious plants in the fall. And here we are with spicebush.

Seen This Week: Witch-Hazel, Whoosh and Brown Leaves

Witch hazel, Schenley Park, 15 Nov 2024 (photo by Kate St. John)

16 November 2024

This week I found witch-hazel (Hamamelis virginiana) blooming in Schenley Park and was startled by a whoosh of wings that passed right in front of me below eye level. I was so startled that I screamed even though I knew that …

The whoosh was an immature red-tailed hawk zipping by to catch a mouse near the wall. In stealth mode the hawk did not flap his wings but he flew pretty close to me. If I didn’t like birds I might have been freaked out. He caught the mouse and I took his picture when he settled down.

Immature red-tailed hawk that buzzed past me in Schenley Park, 15 Nov 2024 (photo by Kate St. John)

By now most oaks have lost their leaves so the predominant color in Schenley and Frick is brown. Brown on the ground and lots of bare trees.

Brown fallen leaves, Schenley Park, 15 Nov 2024 (photo by Kate St. John)

In Schenley Park you can easily see through the woods at ground level because the deer have eaten all the thickets.

In Frick Park I spotted an unusual patch of green, probably an alien plant, so I went down there to check it out.

A green patch in the distance at Frick Park. What is it? 12 Nov 2024 (photo by Kate St. John)

Sure enough, this is an alien — stinging nettle (Urtica dioica), native to Eurasia and Africa. Deer eat stinging nettle in spring and summer but are shunning it at this time of year.

A patch of stinging nettle in Frick Park, 12 Nov 2024 (photo by Kate St. John)

By now the only place to find brilliant reds is in the sky.

Sunrise in Pittsburgh, 10 Nov 2024 (photo by Kate St. John)