Category Archives: Plants & Fungi

plants & fungi

Bees and Electricity

Bumblebee on thistle with pollen grains (photo by Kate St. John)
Bumblebee on thistle with pollen grains (photo by Kate St. John)

Here’s an amazing thing: The hairs on a bumblebee’s body tell it where the flowers are.  It’s done with electricity.

Flowers use scent, patterns, nectar and even ultraviolet colors to attract insect pollinators.  Each flower also has an electric field that says, “I’m here!”  Scientists thought that insects picked up this communication, but how?  A study published in PNAS last May explains that bumblebees sense the electric field with their body hairs.

Bees and flowers are oppositely charged.  Without even trying, bees build up a positive charge on their bodies as they fly.  Flowers are negatively charged and that makes their pollen stick to bees through static electricity.  But the electric field is more than just that static charge.

Positive and negative electric fields: bee and flower (image from Wikimedia Commons)
Positive and negative electric fields: bee and flower (image from Wikimedia Commons)

In the diagram above, imagine that the bee is red and the flower blue.  As a bumblebee approaches the flower, a frisson of excitement passes along its body as its hairs bend in response to the flower’s electric field.  The bee feels the approach. Its hairs are pointing to the flower!

We humans can barely imagine this because we’re not sensitive to electric fields.  As we walk on a carpet we don’t feel the doorknob’s electric field until we touch it and are shocked at the discharge.  The best we can do is see our hair stand up after we rub a balloon on our head.  Here’s Emma at Emma’s Science Blog to show us how:

image linked from Emma's Science Blog: Emma does an experiment with static electricity, April 2014
from Emma’s Science Blog: Emma does an experiment with static electricity, April 2014

 

Now that we know about this communication between bumblebees and flowers, scientists think that lots of hairy insects sense electric fields, too.

I wonder if the house fly sees me with his hairs as well as his eyes as I approach to swat him.

 

Read more about bumblebees and electricity here at mashable.com.

(bumblebee photo by Kate St. John. electric field diagram from Wikimedia Commons.  Emma with balloon linked from Emma’s Science Blog. Click on the field and balloon to see the original images)

p.s. Thanks to Michelle Kienholz for alerting me to this story.

Spotted Wintergreen in the Woods

Striped wintergreen, 2 July 2016 (photo by Kate St. John)
Striped wintergreen, 2 July 2016 (photo by Kate St. John)

Spotted wintergreen’s leaves can be found at any time of year but the plant only blooms from June to August.

The flowers hang like a chandelier from three branches on the main stem. Each flower resembles a lamp: five up swept white petals, paired anthers, and a bulbous green pistil (shown above).

You can tell the difference between spotted wintergreen (Chimaphila maculata) and its close relative Pipsissewa because spotted wintergreen’s leaves are pointed, whorled and distinctly striped on the midrib. For this reason it’s also called “striped wintergreen” — easy to remember when you see the leaves. Where are the spots?

Striped wintergreen (photo by Kate St. John)
Striped wintergreen (photo by Kate St. John)

Striped wintergreen is endangered in Canada, Illinois and Maine and exploitably vulnerable in New York.  I found this one in Beaver County, Pennsylvania.

(photos by Kate St. John)

Montana Flowers And A Tree

Beargrass in bloom, Glacier National Park, June 2016 (photo by Kate St.John)
Beargrass in bloom, Glacier National Park, 29 June 2016 (photo by Kate St.John)

In my final Montana installment, here are some plants seen at Glacier National Park, June 27-30, 2016.

Beargrass grows up to five feet tall with grass-like leaves and a knob of white flowers on top.  As you can see in this poorly lit photo, the beargrass was hard to ignore on the Josephine Lake trail.

Hikers next to beargrass, showing the height of the flower, Glacier National Park, June 2016 (photo by Kate St. John)
Hikers next to beargrass showing the height of the flower, Glacier National Park, 29 June 2016 (photo by Kate St. John)

At Logan Pass we saw Glacier Lilies that resemble our own Trout Lily.

Glacier lily at Logan Pass, Glacier National Park, June 2016 (photo by Kate St.John)
Glacier lily at Logan Pass, Glacier National Park, June 2016 (photo by Kate St.John)

 

And at woodland edges, Pink Wintergreen (Thank you, Dianne Machesney, for identifying this for me) …

Pink Wintergreen, Glacier National Park, June 2016 (photo by Kate St.John)
Pink Wintergreen, Glacier National Park, June 2016 (photo by Kate St.John)

… plus Sticky Geraniums …

Sticky Geranium, Glacier National Park, June 2016 (photo by Kate St.John)
Sticky Geranium, Glacier National Park, June 2016 (photo by Kate St.John)

… and Sego Lilies, the state flower of Utah.

Sego lily, Glacier National Park, June 2016 (photo by Kate St.John)
Sego lily, Glacier National Park, June 2016 (photo by Kate St.John)

 

The meadows were full of wildflowers.

Paintbrush …

Paintbrush species, Glacier National Park, June 2016 (photo by Kate St.John)
Paintbrush species, Glacier National Park, June 2016 (photo by Kate St.John)

Larkspur …

Larkspur, Glacier National Park, June 2016 (photo by Kate St.John)
Larkspur, Glacier National Park, June 2016 (photo by Kate St.John)

Blanket flower (I think. Please correct me if I’m wrong!)

Blanket Flower Glacier National Park, June 2016 (photo by Kate St. John)
Blanket Flower, Glacier National Park, June 2016 (photo by Kate St. John)

and the remnants of Camas flowers that had bloomed in mid-June.

Camas flower, McGee Meadow, Glacier National Park, June 2016 (photo by Kate St.John)
Camas flower, McGee Meadow, Glacier National Park, June 2016 (photo by Kate St.John)

 

And finally, I marveled at the huge Western Redcedars on the wet, western side of Glacier National Park. They are so much bigger than our cedars back home.

Western Redcedar, Glacier National Park, 30 June 2016 (photo by Kate St. John)
Western Redcedar, Glacier National Park, 30 June 2016 (photo by Kate St. John)

 

(photos by Kate St. John)

Daisy Fleabane

Fleabane blooming in Schenley Park, 10 June 2016 (photo by Kate St. John)
Daisy fleabane blooming in Schenley Park, 10 June 2016 (photo by Kate St. John)

You’ve probably seen these small, thin-petaled “daisies” just about everywhere.

Daisy fleabane (Erigeron annuus) is a native plant with a long blooming period — May to October — so you’ll see these flowers for months to come.

Click here to read about fleabane’s daily exercise program (I’m not kidding!) at The Bane of Fleas.

 

(photo by Kate St. John)

Sneaky Orchids

Most flowers offer food to attract pollinators.  Trumpet vine, for instance, provides nectar for hummingbirds who incidentally pick up pollen and transport it to the next flower.

But some orchids have no food to offer.  Instead they look and smell like sexy female insects so the males will attempt to mate with them.  In doing so the orchids’ pollen clumps (pollinia) become stuck to the male insects and are taken to the next flower.

Watch the video above from BBCWorldwide to see how it’s done.

Sneaky orchids!

 

Thanks to Bonnie Isaac, President of the Botanical Society of Western Pennsylvania, for pointing out this cool video in the Society’s second quarter bulletin.

(video from BBCWorldwide on Youtube)

Spots Under The Leaf

Sporogenesis under the fern leaf (photo by Kate St. John)
Sporogenesis under the fern leaf (photo by Kate St. John)

Ferns look simple.  They don’t have flowers so they must be boring, right?  Not!

Look under the leaves(*) in June and you’ll see spots, called sporangia, that are creating spores for the next generation.  Here’s another example.

Sporangia under fern leaf (photo by Kate St. John)
Sporangia under the fern leaf (photo by Kate St. John)

The spores are single haploid cells with only one set of chromosomes, just like the sperm and eggs of mammals. But the spores don’t “mate” with anything.  Instead the next generation grows directly from the spore.  It’s a small heart-shaped green thing called a prothallus and it’s also haploid.  The prothallus eventually produces sperm and eggs that unite in water to become the next generation, the leafy fronds.

The frond phase is diploid with two sets of chromosomes.  In time, the plant produces sporangia and the process repeats.

Because of this fern “parents” and “kids” look nothing like each other: prothallia, leaves, prothallia, leaves … on and on and on.

Confused? Here’s a video that explains it better than I can.

 

(*) Some ferns, such as sensitive fern, produce spores on parts of the plant that have no leaves. Others, such as hay-scented fern, don’t display their sporangia as openly as those pictured above.  Read more about ferns here.

(photos by Kate St. John, video posted by Gabe Fierro on YouTube)

Poppy Day

Red poppies (photo from Lest We Forget via Wikimedia Commons)
Red poppies (photo from Lest We Forget via Wikimedia Commons)

It’s Poppy Day.

When I was a child, we wore a red paper flower on a wire stem on Memorial Day. They were offered by Veterans of Foreign Wars to passersby for a donation to help veterans. The paper flowers symbolize the Remembrance Poppy from World War I.

Poppies became a veterans’ symbol thanks to the tireless efforts of Moina Michael, “The Poppy Lady,” who was inspired by the poem In Flanders Fields by John McCrae.  McCrae wrote the poem for a friend who died at the Second Battle of Ypres in Flanders (Belgium) in 1915.  After the battles, poppies bloomed among the graves.

At first her idea did not catch on, but in 1922 the Veterans of Foreign Wars (VFW) adopted the poppy as their official memorial flower.  That year they distributed paper poppies made in France but in 1924 they brought the program stateside to the first Buddy Poppy factory, located in Pittsburgh and manned by disabled veterans.

Ninety years later the Buddy Poppies are still assembled by disabled and needy veterans at VA Hospitals across the country and Buddy Poppy fund drives focus on Memorial and Veterans Days.   (Watch a video about the VFW Buddy Poppy program here.)

That’s why I think of poppies today.

 

(photo from Lest We Forget via Wikimedia Commons. Click on the image to see the original)

p.s. Did you know that growing poppies used to be illegal in the U.S.?  The Opium Poppy Control Act of 1942 was repealed in October 1970 but the law remains ambiguous.

A Closer Look At Yarrow

Yarrow in bloom (photo by Kate St. John)
Yarrow in bloom (photo by Kate St. John)

Clusters of white flowers are blooming in fields and open forests in western Pennsylvania.

Yarrow (Achillea millefolium) is a perennial in the Aster family, native to the northern hemisphere.  The genus name, Achillea, refers to the Greek hero who reportedly used yarrow to treat his soldiers’ wounds.  The species name, millefolium, means “a thousand leaves.” Look closely at the tiny feather-like leaves and you’ll see they’re arranged in a spiral on the stem.

Yarrow’s flowers deserve a closer look, too.  The central disk is a cluster of tiny flowers and the petals (rays) are individual flowers with nectar openings where the ray connects to the flower head.

In North America we have both native and introduced species and they hybridize so it’s hard to tell who’s who.

Watch for yarrow blooming this month and into June.

 

(photo by Kate St. John)

Lady Slippers In A Cage

Pink lady's slipper, Ohiopyle State Park, 18 May 2016 (photo by Kate St. John)
Pink lady’s slipper, Ohiopyle State Park, 18 May 2016 (photo by Kate St. John)

This flower is in a cage at Ohiopyle State Park.

Pink lady’s slipper (Cypripedium acaule) orchids are found in Pennsylvania, but increasingly rare because deer like to eat them.  The deer bite off the flower, leaving the stem and leaves behind.

Here’s what the entire flower looks like.  Imagine it with a headless stem!

Pink lady's slipper, Ohiopyle State Park, 18 May 2016 (photo by Kate St. John)
Pink lady’s slipper, Ohiopyle State Park, 18 May 2016 (photo by Kate St. John)

 

And here’s how these beautiful flowers are protected: a deer exclosure.  Notice the 10-foot high fence with the yellow X.  The sign explains why the exclosure is necessary.

Deer exclosure at Ohiopyle State Park containing pink lady's slippers, 18 May 2016 (photo by Kate St. John)
Deer exclosure at Ohiopyle State Park containing pink lady’s slippers, 18 May 2016 (photo by Kate St. John)

Outside the fence I found five lady’s slippers with the chopped off heads.  🙁

We humans are the reason why there are too many deer in Pennsylvania and, so far, we haven’t the will to reduce their population to a sustainable level.

In the meantime we’re putting our most precious wildflowers in cages.

 

(photos by Kate St. John)