On Throw Back Thursday:

This mushroom is easy to find right now.  It’s edible(*) and it tastes like chicken so it’s called Chicken-of-the-woods (Laetiporus sulphureus).

I found a huge one years ago with a chicken-sized chunk taken out of it.  Apparently a mushroom hunter had been there ahead of me, as described in this 2010 article: Chicken of the Woods

But don’t listen to me when it comes to mushrooms.  (I know nothing!)  Learn about Chicken-of-the-woods in this video by Adam Haritan of Learn Your Land.

(*) Note that an “edible mushroom” can sometimes be poisonous.  Be sure you know what you’re doing!

(photo by Chuck Tague, video by Adam Haritan)

24 September 2017

In July and August I noticed something I’d never seen before along the trails of western Pennsylvania — scattered instances of leaves turning white.

The leaves had been green but now their tips or even whole branches are white. The plant below had advanced to the stage where some of the stems were completely white.

The condition is called chlorosis and it means the plant is not producing enough chlorophyll to look green.  Since chlorophyll uses sunlight to make food for the plant, it’s a sign the plant is in distress.  But why?

Causes of chlorosis are wide-ranging.  Here’s the list from Wikipedia:

• a specific mineral deficiency in the soil, such as iron, magnesium or zinc
• deficient nitrogen and/or proteins
• a soil pH at which minerals become unavailable for absorption by the roots
• poor drainage (waterlogged roots)
• damaged and/or compacted roots
• pesticides and particularly herbicides may cause chlorosis, both to target weeds and occasionally to the crop being treated.
• exposure to sulphur dioxide
• ozone injury to sensitive plants
• presence of any number of bacterial pathogens, for instance Pseudomonas syringae pv. tagetis that causes complete chlorosis on Asteraceae.

The white plants I’ve seen are isolated incidents among hundreds of green plants. Some of these causes would have created damage on nearby plants as well. It seems to me that these causes don’t apply: Poor drainage, Pesticides or herbicides, Exposure to sulphur dioxide air pollution, Ozone injury to sensitive plants [These are hardy weed plants.]

Interestingly, the plants I photographed are in the Aster Family (Asteraceae) and one of them has complete chlorosis.

Was the 2017 growing season especially bad for the bacteria mentioned above?  Or does chlorosis happen every year and I’ve just not noticed?

If you know more about this condition in the wild, please leave a comment.  I’m really curious!

(photos by Kate St. John)

Any trip outdoors this month will find a lot of goldenrods in North America.  Here are just a few of the species I’ve photographed over the years.  All of them are different.

Can I tell you their names? No. Goldenrods are notoriously hard to identify.

Above, a beautiful bushy goldenrod at Acadia National Park in Maine.

Below, the classic goldenrod shape in Pittsburgh: a tall plant with narrow alternate leaves and a tassel of yellow flowers on top.  To identify it I’d need more information than the photo provides.  For instance:  Do the leaves have two or three prominent veins?  Are they toothed or entire?  Is the main stem smooth or downy or both?

In the photo below: An unusual goldenrod shape photographed in Pittsburgh. The plant reaches out horizontally with flowers perched in clusters on top of the stem. The leaves are long and narrow.  Perhaps it’s blue-stemmed or wreath goldenrod.

This one is a stand-up spike of yellow flowers with egg-shaped alternate leaves, found in Pittsburgh.

Is this goldenrod the same species as the tall tassel above?  I don’t know.

I’ve never seen white goldenrods in Pittsburgh. This spike of white flowers was photographed at Acadia National Park in Maine.

And finally, a ball-shaped flower cluster with long leaves, growing in a granite crack at Acadia National Park.

So much variety.  So many goldenrods.  And often so hard to identify.

(photos by Kate St.John)

Early in June I noticed curled leaves on all the trees and bushes by a road in my neighborhood.  Though I suspected it was caused by herbicide I was puzzled that other plants were not brown and dead.  Why would someone use an herbicide that maimed but didn’t kill?  I forgot about it until I saw a photo of soybeans that looked the same way.

This summer, farmers from Arkansas to Ohio and North Dakota have experienced crop loss from a new formulation of the herbicide dicamba.  Dicamba has been used for a long time but this spring Monsanto, BASF and DuPont reformulated it for use with new genetically engineered dicamba-resistant soybeans.

The problem is this:  If your neighbor plants the new soybeans your fields could be affected.   The new dicamba volatilizes (evaporates) from the soil and leaves where it’s applied and drifts as much as half a mile causing crop loss and low yield in everything else including non-resistant soybeans, tomatoes, watermelons, grapes, pumpkins and other vegetables.

At first affected farmers were reluctant to report a problem caused by their neighbors but crop losses have been so severe — up to 80% — that Arkansas, Missouri and Tennessee placed restrictions on dicamba use this summer and many have asked EPA to reconsider its approval.

I’ll never know if dicamba was used in my neighborhood but I know now that an herbicide can do this.

Meanwhile the leaves are still in distress.  I took these photos last week.

(photos by Kate St. John)

Cardinal flower (Lobelia cardinalis) is such a deep red color that it looks like velvet.

From a distance you’ll see this perennial along streambanks, in wet places and swamps. The plant is as much as four feet tall.

It blooms in late summer and early fall, just in time for migrating hummingbirds to sip its nectar on their way south.

(photo by Kate St. John)

Ironweed is one of my favorite August flowers but it’s hard for me to photograph.  Its purple color doesn’t ring true on my digital camera (too blue!) and the plant is so tall that I’ve never been able to replicate Chuck Tague’s quintessential view of it, below.

In August ironweed is truly impressive.  At seven to ten feet tall it’s topped by a corymb (flat-topped cluster) of 30 to 50 deep purple flowers made up of 5-lipped florets. Dark red stems support long, alternate, lance-shaped leaves that are rough to the touch.

You’ve probably seen ironweed from the highway as it’s the only tall flower left standing in cow pastures.  Its stem is so tough that cows refuse to eat it, thus the ironweed name.  On foot you’ll find it in ditches, moist meadows and along stream banks.

In Pennsylvania there are two native species — tall ironweed (Vernonia gigantea) and New York ironweed (Vernonia noveboracensis) — distinguished by their bracts and florets per flower:

• Tall ironweed (gigantea) has blunt or short-pointed bracts and 13-30 florets.
• New York ironweed (noveboracensis) has long thread-tipped bracts and more than 30 florets per flower.

When you’re up close with ironweed you can count its florets.  My photo from Frick Park shows less than 30 so this would be tall ironweed.

Or maybe not!  Tall and New York ironweeds hybridize.

Tall ironweed is listed as endangered in New York state and invasive in Kentucky.  I wonder why.

(photo credits: close up by Kate St. John, corymb by Chuck Tague)

*A corymb is a flat-topped cluster.  An umbel is shaped like an umbrella, rounded on top.

Though we haven’t had many hummingbirds this year, Pittsburgh’s trumpet creeper is waiting to attract them.

Trumpet vine or trumpet creeper (Campsis radicans) is a woody vine native to eastern North America.  It’s so well adapted to the forest edge that it aggressively climbs up to 35 feet to reach the sun.

Its beauty and scent are attractive to gardeners but it requires ruthless pruning.  The Lady Bird Johnson Wildflower Center says, “To keep it in check, plant it near concrete or an area that you can mow; mowing down the suckers will discourage them.”

The flower is specially shaped for pollination by ruby-throated hummingbirds, the only hummingbird in this plant’s native range.  The tubes are large and the anthers held high. The insect above is too small to pollinate it.

Learn more in this video by the Capital Naturalist.

As a trumpet for hummingbirds, it’s probably so fragrant because ruby-throats like its scent.  Remember: we learned this month that birds can smell.

(photo by Kate St. John; video by The Capital Naturalist on YouTube)

There’s a tall plant in the Composite family (Asteraceae) that used to confuse me, especially in early summer. Here’s a trick for identifying mugwort.  It’s everywhere right now.

Mugwort or common wormwood (Artemisia vulgaris) is an aromatic perennial native to Europe, Asia, northern Africa and Alaska(!).  It may have been brought here for medicinal purposes, but it spreads easily along roadsides and waste places.  I’m surprised it’s not on Pennsylvania’s Invasives list.

In early summer when mugwort is knee high, it looks like chrysanthemums because its leaves are similar — sharply lobed.  The trick for telling them apart is this:  Look under the leaf. The underside of a mugwort leaf is white (above).

By late August mugwort is three to eight feet tall with insignificant green flowers clustered at the leaf joints and at the tips of the stems.  The leaves near the flowers look different. They’re linear, not lobed.

But it isn’t beautiful.

In August a mugwort patch looks tall and messy.

Wondering what it is?  Flip a leaf.  It’s probably mugwort.

(photos by Kate St.John)