Category Archives: Plants & Fungi

Mallards Help Plants in Winter

Flock of mallards in Järvenpää, Finland (photo from Wikimedia Commons)

26 January 2022

Since plants are rooted to the ground, the only way they find a new place to live is through seed dispersal. Pressure to find new places is intensified by climate change but a study published this month in Science points out:

Half of all plant species rely on animals to scatter their seeds through hitchhiking in scat, fur, or beaks. When mammal and bird populations decline, so does the ability plants have to disperse their seeds and adapt to climate change. Loss of mammals and birds cuts a plant’s ability to adapt by 60 percent.

With Fewer Animals to Move their Seeds, plants are stuck in threatened habitats

Mallards to the rescue.

In 2017 study at Utrecht University found that mallards (Anas platyrhynchos) significantly help plants and isolated wetlands by dispersing seeds in winter.

Mallards change their diet during the year, from carnivorous in the breeding season to vegetarian in winter. During migration they stop to eat then disperse seeds later along the way. This particularly helps isolated wetlands that would not gain new seeds otherwise.

Mallards also help every day on their wintering grounds by moving back and forth from roosting to feeding areas. Where there is hunting pressure you might not see this because mallards change their ways: eating at night and hiding at the roost during the day.

Mallards in flight (photo by Imran Shah via Wikimedia Commons)

Mallards are the most abundant duck species on earth and perform this seed dispersal service on four continents: North America, Europe, Asia and Africa.

Find out more at Wintering Ducks Connect Isolated Wetlands by Dispersing Plant Seeds.

(photos from Wikimedia Commons; click on the captions to see the originals)

In The Land of Mistletoe

Tree with mistletoe, Tidewater Virginia (photo by Kate St. John)

24 December 2021

This weekend we’re in Tidewater Virginia where the trees are bare but not empty. Many hold green balls of American mistletoe (Phoradendron leucarpum), a hemi-parasitic plant that extracts water and nutrients from tree branches while it also photosynthesizes.

Mistletoe in tree, Tidewater Virginia (photo by Kate St. John)

At this time of year it sports sprays of white berries that are toxic to humans but good for birds.

American mistletoe, Phoradendron leucarpum (illustration from Wikimedia Commons)

While the birds eat the berries I marvel that mistletoe is common here. We don’t have it in western Pennsylvania (‘x’ = Pittsburgh).

Occurrence of American mistletoe (map from Wikimedia Commons plus ‘x’ for location of Pittsburgh)

At home we buy mistletoe in a store to carry on this Christmas tradition.

It’s above us in the backyard in the land of mistletoe. Perhaps that’s why Virginia is For Lovers.

(photos by Kate St. John and from Wikimedia Commons; click on the captions to see the originals)

Cactus With A Pittsburgh Connection

Saguaro silhouettes (photo from Wikimedia Commons)

1 December 2021

This iconic symbol of the Sonoran Desert has a Pittsburgh connection.

The only member of its genus, the saguaro cactus was given the scientific name Carnegiea gigantea to honor Andrew Carnegie who established the Desert Laboratory on Tumamoc Hill for native plant research in Tucson in 1903.

Saguaro cacti at Saguaro National Park (photo from Wikimedia Commons)

Though now a symbol of deserts everywhere, this unusual “tree” is native only to the Sonoran desert of Arizona, California and northwestern Mexico.

Saguaro (pronounced “sah-WAH-ro“) grows to 50 feet in height; its tremendous weight, up to nine tons, is supported by a skeleton of about two dozen spongy, wooden rods. Accordion pleats [expand and] contract as they gain and lose moisture. White flowers open after nightfall and close by late afternoon the following day. Saguaro has fleshy red fruit. Giant, leafless, columnar tree cactus with massive, spiny trunk and usually 2-10 stout, nearly erect, spiny branches. Saguaro cactus account

The saguaro’s woody skeleton is exposed when the plant dies. Click here to see a skeleton with arms.

Skeleton of saguaro cactus (photo by Jay Iwasaki via Flickr Creative Commons license)

The pleats expand and the trunk looks fat after the rainy season.

Saguaro with expanded accordion pleats (photo by Kate St. John)

The plant reproduces via cross-pollinated flowers that bloom at the tips. The saguaro grows arms to produce more flowers.

Flowers are at the tops of saguaro branches (photo from Wikimedia Commons)
Saguaro flowers closeup (photo from Wikimedia Commons)

Birds, animals and humans make use of this cactus.

Native Americans made use of the entire cactus. … Gila woodpeckers and gilded flickers make round holes near the tops of branches for nests that are used afterwards by elf owls, cactus wrens, and other birds. Wildlife, especially white-winged doves, consume quantities of the seeds. Saguaro cactus account
Gila woodpecker feeds on a saguaro flower (photo from Wikimedia Commons)
White-winged dove at saguaro fruit (photo from Wikimedia Commons)

Saguaros can only survive where the temperature never drops below 28oF. They grow in Phoenix because of its urban heat island.

Read more cool facts about saguaro in this abbreviated account by C A Martin at Arizona State.

(photos from Wikimedia Commons and Jay Iwasaki on Flickr with Creative Commons license; click on the captions to see the originals)

Leaves and Merlins

Hornbeam seeds with spider/insect cocoons, 21 Nov 2021 (photo by Kate St. John)

27 November 2021

Nature was busy this week. Spiders or insects wove tiny white cocoons inside this hornbeam seed structure. Chickadees look for these cocoons and eat the tasty treats inside.

As predicted, Schenley Park’s gingkos lost all their leaves in a single day — 20 November.

Gingkos shed all their leaves on Schenley Drive, 20 Nov 2021 (photo by Kate St. John)

Norway maples were not far behind on the 24th.

Three trees on 24 Nov 2021: 1 bare, 2 maple fallen leaves, 3 red oak leaves waiting (photo by Kate St. John)

I went to Schenley Park golf course to find a merlin just before sunset on 23 November. Instead I found three merlins jostling for the highest perch on the highest hill. The tallest snag in this photo is not the highest perch but the dot on top is merlin #2 of 3 who is watching the airshow as 2,500 crows fly over from the Allegheny Valley to where? Crows were still passing overhead when I left.

After sunset the sky still glowed.

Cathedral of Learning, Heinz Chapel, and WQED’s transmission tower after sunset 23 Nov 2021, Pittsburgh, PA (photo by Kate St. John)

(photos by Kate St. John)

Invasive Barberry is Banned At Last

Japanese barberry in October (photo by Kate St. John)

17 November 2021

If you’ve ever tangled with Japanese barberry (Berberis thunbergii) you know this thorny plant has pretty berries but grows quickly into an impenetrable hedge. Imported for landscaping in the late 1800s, it has gone wild in the state and invaded the woods. Deer refuse to eat it. Despite its invasive attributes it was still sold for landscaping in Pennsylvania until now.

Last month the PA Department of Agriculture added Japanese barberry (Berberis thunbergii) to the state’s list of noxious weeds. As of 8 October 2021 it cannot be legally sold or cultivated in the state though you may see it in nurseries while enforcement is phased in over the next two years. In the meantime, you should not be offered Japanese barberry as a landscaping choice; don’t buy it.

By fall 2023 Japanese barberry should be a thing of the past in the landscaping world but it is rampant in the woods and already may be in your yard. Cultivars were bred for colorful leaves from yellow-green to red to purple.

A reddish variety of Japanese barberry in a garden (photo from Wikimedia Commons)

In the wild and waste places it reverts to plain green leaves.

Japanese barberry in the woods in May, Connecticut (photo from Wikimedia Commons)

No matter where you find it don’t get too close. If you brush against it — or heaven forbid, have to bushwhack through it! — check your clothing for ticks. Japanese barberry is a magnet for black-legged ticks that harbor Lyme disease. As Wikipedia explains:

It is hypothesized that spread of barberry is correlated with the spread of Lyme disease. Tick numbers are higher in areas with thick barberry understories, as opposed to areas with controlled barberry or no barberry. In one study, 280 ± 51 adult black-legged ticks, Ixodes scapularis, were found per hectare in a barberry infected area, while only 30 ± 10 adult black-legged ticks were found per hectare in otherwise similar area with no barberry present.

Wikipedia Berberis thunbergii account

Do you have Japanese barberry in your yard? Did you get Lyme disease in your garden? After I took the photo at top I found a tick on my pants. Beware!

This 2016 video from Minnesota shows how to recognize Japanese barberry in the wild and then describes how they’ve tried to eradicate it in Minnesota. Flames!

Thankfully Pennsylvania will no longer add new barberry to the landscape. Invasive Japanese barberry is banned at last.

(photos by Kate St. John and from Wikimedia Commons, see the captions)

Fall Colors, Frost, and Bad Air

Colorful trees at Moraine State Park, 3 Nov 2021 (photo by Kate St. John)

8 November 2021

Last week began as a warm colorful autumn and ended with frosty mornings. This week begins with bad air.

Before last week’s frost I found splashes of fall color including this amaranth in an unusual place at Phipps Conservatory. Click here to see where this red plant was growing.

Amaranth in an unusual spot at Phipps Conservatory, 30 Oct 2021 (photo by Kate St. John)
Colorful leaves at Schenley Park, 30 Oct 2021 (photo by Kate St. John)

On 4 November the leaves glowed yellow as the sun gained altitude at Frick. When the sun melted the frost, leaves quickly loosened and dropped from the trees.

Sun through golden trees on a frosty morning at Frick Park, 4 Nov 2021 (photo by Kate St. John)

On Saturday morning at Yellow Creek State Park the frost was beautiful, ephemeral and cold. Hoarfrost decorated the weeds in the parking lot.

Hoarfrost on a grassy weed, Yellow Creek State Park, 6 Nov 2021, 9:39am (photo by Kate St. John)
Hoarfrost at Yellow Creek State Park, 6 Nov 2021, 9:39am (photo by Kate St. John)

Frost remained in a tree’s shadow but not for long.

Frost in the shadow, Yellow Creek State Park, 6 Nov 2021, 9:49am (photo by Kate St. John)

Last week I re-learned how to dress for winter. This week will be warm with highs in the 60s, lows in the 40s, temperature inversions and bad air in Pittsburgh.

Roger Day captured these views of the Mon Valley yesterday morning, 7 November, from Frick Park’s Riverview overlook. The Allegheny County Health Department has issued an air pollution warning and the state DEP has issued a Code Orange warning. Read more here.

Edgar Thompson Works in Braddock pouring smoke, seen through smog at Frick Park, morning of 7 Nov 2021 (photo by Roger Day)
Inversion: Edgar Thompson Works in the distance, Frick Park, morning of 7 Nov 2021 (photo by Roger Day)
Inversion: Kennywood seen through smog from Frick Park, morning of 7 Nov 2021 (photo by Roger Day)

Don’t breathe!

(photos by Kate St. John & Roger Day)

Eat Sparingly

Barrel cactus with fruit, Reach 11 Recreation Area, Phoenix AZ, 24 Oct 2021 (photo by Kate St. John)

1 November 2021

Most intriguing on my daily walks last week in Phoenix were the barrel-shaped yellow fruits atop fishhook barrel cactus (Ferocactus wislizeni). I missed the flowering (click here to see) but the fruits may persist for more than a year after the flowers fade into dried brown tufts on top of the fruits.

Barrel cactus fruit (photo from Wikimedia Commons)

A closer look shows a few seeds remaining where each fruit broke off.

Seeds underneath barrel cactus fruit, Reach 11 Recreation Area, Phoenix AZ, 24 Oct 2021 (photo by Kate St. John)

There were no fruits on the ground near this specimen at Reach 11 Recreation Area, probably because the park has so many javelinas. I saw the footprints of these peccaries (not pigs) but didn’t see any of the animals. Here’s what one looks like in a photo from Wikimedia Commons.

Javelina in Phoenix (photo from Wikimedia Commons)

Javelinas and squirrels eat the lemony-flavored fruits and some websites say we can eat them too, but sparingly. The fruit is mucilaginous like okra. The cactus contains oxalic acid, a poison that causes nausea and diarrhea in low doses and death in high doses …

… which might explain the other evidence left behind by the javelinas. Were the javelinas sick to their stomachs?

“That meal was great,” said the javelinas, “but I feel a little whuugh.”

(photos from Kate St. John and Wikimedia Commons)

Halloween Colors in Nature

Milkweed bugs, Sept 2021 (photo by Kate St. John)

31 October 2021

Some things are naturally black and orange like Halloween, often because they are poisonous. This is especially true for milkweed bugs (above) and monarch butterflies (below). The colors say “Notice me and stay away.”

Monarch butterfly on swamp milkweed, July 2014 (photo by Steve Gosser)

Red admiral butterflies are orange-red and dark brown, almost black. Their host plant is nettle. Are they poisonous?

Red admiral, Germany (photo from Wikimedia Commons)

Jack-o-lantern mushrooms (Omphalotus olearius) are well named for their color. Did you know the gills of these mushrooms glow green in the dark? Unfortunately it’s never dark enough to see this in Schenley Park where I found the mushrooms in late September.

Jack-o-lantern mushrooms in Schenley Park, 25 Sep 2021 (photo by Kate St. John)

Pumpkins are native to Central America while goats are native to southwest Asia and eastern Europe. Here the domesticated versions meet up. The goats win.

Goats eating discarded jack-o-lantern (photo by Rebecca Siegel via Wkimedia Commons)

Happy Halloween!

(photos by Kate St. John, Steve Gosser, and from Wikimedia Commons)

Butterflies on Broom

American snout butterfly on desert broom, Box Bar Recreation Area, Arizona, 23 Oct 2021 (photo by Kate St. John)

30 October 2021

While visiting Arizona I noticed that one plant in particular attracted lots of butterflies. The plant above was covered in snouts (Libytheana carinenta) though only one shows up in my photo.

Eventually I learned that the plant is desert broom (Baccharis sarothroides), a dioecious shrub with very different male and female flowers (male on left, female on right below). The male flowers get all the attention from butterflies.

Male and female flowers on desert broom, Box Bar Recreation Area, Tonto National Forest, 23 Oct 2021 (photo by Kate St. John)

It’s hard to imagine how the female flowers become pollinated when nothing seems to visit them.

Next month after the flowers are fertilized the seeds will be ready to disperse. I’m sorry I’ll miss the period when the brooms look fluffy.

(photos by Kate St. John)

Which Ones Are Drupes?

Cherries (photo from Wikimedia Commons)

17 October 2021

In botany a drupe is a simple fleshy fruit that contains a single hard pit with a seed inside it.

Some of the photos in this article show drupes, some do not. Which is which?

White peaches with a cross section (photo from Wikimedia Commons)
Black walnuts just fallen from the tree (photo from Wikimedia Commons)
Avocado with a cross section (photo from Wikimedia Commons)
Green (unripe) and black (ripe) olives (photos from Wikimedia Commons)

Which are drupes? Leave a comment with your answer.

See the comments for the answer.

(photos from Wikimedia Commons; click on the captions to see the originals)