Category Archives: Plants & Fungi

plants & fungi

The Holly and The Ivy

Plants & Fungi, Trees

The Holly and The Ivy is one of my favorite Christmas tunes. This week the lyrics inspired me to learn more about holly.

The holly and the ivy, when they are both full grown,

Of all the trees that are in the wood, the holly bears the crown.

Like mistletoe, holly is a European Christmas tradition that easily transferred to North America.  In Europe they decorate with Ilex aquifolium. When the colonists arrived in Virginia they found an abundance of the very similar Ilex opaca.

Since ancient times holly has been associated with the winter solstice because it remains green all year.  Each evergreen leaf with its sharp spiky edges remains on the tree for two to three years and only falls in the spring when a new bud forces it off the branch.

The holly bears a blossom as white as lily flower…

In Esther Allen’s photo you can see the holly’s white flowers which bloom in May and are pollinated by bees, wasps, ants and moths.  Hollies are dioecious — some trees are male, others are female.  Only the female trees bear fruit.

The holly bears a berry as red as any blood…

Holly berries stay on the trees in winter and are often eaten by birds.  Esther’s photo shows that uneaten berries can persist into spring alongside the flowers.

The holly bears a prickle as sharp as any thorn…

The leaf edges are sharp.  No doubt about it.  I tested one with my finger.  Ow!

The holly bears a bark as bitter as any gall…

This, I did not test.  I’ll take their word for it.

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The holly and the ivy, when they are both full grown,

Of all the trees that are in the wood, the holly bears the crown.

…a crown of thorns, greenery and red berries.  Very beautiful.

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(photo by Esther Allen, remembered fondly this Christmas)

Mistletoe in the Wild

Plants & Fungi, Trees

The Christmas tradition of kissing under the mistletoe came to North America with European colonists. Back home they used Viscum album for this purpose.  Here they found a very similar native plant, Phoradendron leucarpum, that worked just as well.

Growing up in Pittsburgh I always thought of mistletoe as an exotic import that could only be bought in the store.  I never saw it in the wild because we’re just north of its range but it’s quite common in the south, noticeable as balls of greenery in bare trees at this time of year.

Mistletoe is a hemiparasitic plant that grows on tree branches, sending its roots into the bark.  It is partly (hemi) parasitic because it produces its own food through photosynthesis but needs its host for water and minerals.  It doesn’t normally kill its host.  That would be suicidal.  It needs its host to survive.

Like many plants mistletoe relies on birds to spread its seeds but there’s a twist.  Birds like to eat mistletoe berries and they don’t digest the seeds but the seed must survive the bird’s gut and stick to a tree branch long enough to germinate.  To do this the seeds are coated in a very sticky substance.  Birds either avoid swallowing the seeds and wipe their sticky bills on a branch, or they swallow the seed and fly elsewhere to “deposit” it.  Favorite perching trees receive more deposits. That’s why you see a lot of mistletoe in some trees but not others.

Some birds are mistletoe specialists.  In the desert West, phainopeplas get their water and nutrition from desert mistletoe for much of the year.  A phainopepla can eat up to 1,100 mistletoe berries per day.

Though mistletoe’s parasitic nature gave it a bad name, recent studies have shown that animals, birds and habitat are more diverse where mistletoe thrives.  It apparently holds the ecosystem together … like a kiss joins a couple.

Have you hung a sprig of mistletoe this year?

(photo of mistletoe in Delaware by Charlie Hickey)

There’s Something In The Air

Plants & Fungi, Schenley Park, Weather & Sky

As I’ve snapped photographs of bark for my winter tree identification series, I’ve had no trouble finding clean, lichen-free trees in Schenley Park.  It turns out the lack of lichens is bad news for our air quality.

Lichens are two organisms that operate as one, a symbiotic partnership of a fungus with a green or blue-green algae (sometimes all three).  The algae’s photosynthesis feeds the fungus.  The fungus gathers and retains water and nutrients and protects the algae.

This amazing combination allows lichens to thrive in some of the harshest habitats on earth but they’re sensitive to air pollution.  The ones that grow on trees are epiphytes, totally dependent on the surrounding air and precipitation for their nutrition.  Ultimately their tissues absorb elements in concentrations that mimic what’s in the air.

We’ve known for a long time that there’s a correlation between the absence of lichens and poor air quality.  Back in 1866, the Finnish botanist William Nylander showed that lichens were present in the Luxembourg Gardens that had disappeared from the polluted sections of Paris, France.  Sadly, air pollution increased in Paris and within 30 years the Luxembourg Gardens’ lichens had disappeared as well.

Lichens are used in air quality studies today because they are widespread, accurate indicators and far less expensive than man-made monitors.  You don’t have to be an expert to participate.  In the 1960’s schoolchildren in Great Britain gathered data in a nationwide lichen-based air quality study that produced the “Mucky Air” map.  Here’s a list of a few more recent lichen studies:

Even if you can’t identify lichens you can make a rough guess of the local air quality by the types of lichens you see.  Basically, “the further it stands out from the tree, the cleaner the air.”  Crusty lichens (crustose) are the hardiest because they have the least surface area, leafy (foliose) lichens are in the middle, shrubby (fruticose) lichens are the most sensitive.  Hypogymnia physodes, a foliose lichen pictured above, is often used as an indicator species because it’s widely distributed and it “stands up.”  I’ve seen lichens like this in Maine but not in Pittsburgh.

Lichens are especially sensitive to sulfur dioxide (SO2).  So are people.  In Pennsylvania most of our SO2 is produced by coal-burning power plants and coking facilities.   High SO2 causes respiratory distress and triggers asthma so it’s been regulated since the Clean Air Act of 1970.  Lichens have rebounded in many areas of the U.S. since then.

In June 2010 EPA issued tighter 1-hour SO2 standards (75 ppb, measured hourly) to protect public health from high short term exposures ranging from 5 minutes to 24 hours.  Because we’ve been measuring SO2 for so long, we already know that the Pennsylvania counties of Allegheny, Beaver, Indiana and Warren have exceeded the new SO2 standard.  Coal-burning facilities in these counties will have to control their SO2 emissions even further.  As they do, we’ll all breathe a little easier.

And we’ll have more lichens in the future.

(photo in the public domain from Wikimedia Commons. Click on the photo to see the original.)

Quiz: What Plant?

Plants & Fungi, Quiz

I discussed epiphytes a couple of days ago because I wanted to use this beautiful photo as a quiz. 

Though this looks like an artistic squiggle it’s actually a close-up of a plant. 

Here are some hints to its identity:

  • It’s an epiphyte.
  • It’s native to the southeastern U.S. where the climate is warm with high humidity.
  • It has tiny inconspicuous flowers.  (As many times as I’ve seen this plant I’ve never noticed any flowers.)
  • Its leaves are alternate, thin, heavily scaled and curved.  These are its leaves. 
  • The leaves appear to form long chains.
  • Big hint: It’s commonly found hanging from southern live oaks and bald cypress trees.

Can you guess what it is?

Leave a comment with your answer.

(photo by Ernest V. More in the public domain on Wikimedia Commons)

Epiphyte

Plants & Fungi


The Upon Plant:

That’s what epiphyte means in Greek (epi=upon, phyte=plant) and that’s what an epiphyte is:  a plant upon a plant.

I never thought about this word until I saw some interesting epiphytes in the forest while visiting my family in southeastern Virginia.

True epiphytes are sometimes called air plants because they collect their water and nutrients from rainfall, mist, dust and the surrounding air.  Though they’re held aloft by a host plant they aren’t parasites and never directly harm their host.

As proof, here’s a photo of epiphytes growing on telephone wires in Bolivia.

I’ve seen this in Florida too.  I’m sure it annoys the phone company.

We normally think of epiphytes as tropical plants like the red orchid pictured above, but all kinds of plants-upon-plants grow wherever there’s enough humidity or rainfall and clean air.

Mosses, lichens and ferns are the epiphytes I usually see in Pennsylvania.  They seem almost boring because I’m so used to them.

Do you have interesting epiphytes where you live?

(photos via Wikimedia Commons.  Click on each photo to see the originals)

Saved By Its Beauty

Beyond Bounds, Plants & Fungi

As the sunlight shines through this leaf, each vein is illuminated.

Alocasia sanderiana is beautiful up close and from afar.

Its leaves are arrow-shaped, dark green, and very shiny with prominent pale green veins.  The leaf edges are so amazingly wavy that in English it’s called the kris plant, named for the kalis (or kris) daggers of its homeland.

Here’s what the whole leaf looks like:

Alocasia sanderiana is native to the Philippines but is critically endangered in the wild.  It grows in only two locations, both legally protected, but the protection is not enforced.  Its existence is threatened by logging and by being collected as a house plant.

Ironically, if the kris plant disappears from the wild, its beauty will save it from extinction because it’s been propagated “in captivity” for many, many years.

(close-up of an Alocasia leaf by Joan Guerin; whole-leaf photo from Wikimedia Commons)

Witchy Things

Books & Events, Plants & Fungi, Schenley Park
Witches hat mushroom (Hygrophorus conicus) (photo by Dave Powell, USDA Forest Service, from Bugwood.org)

31 October 2011

Happy Halloween!   Here’s a selection of witchy things to celebrate the day.

Witches hat mushroom (Hygrophorus conicus), shown above, is common in the forest at this time of year..

Witch-hazel trees are blooming now in Schenley Park.

Witch-hazel blooming in Schenley Park (photo by Kate St. John)
Witch-hazel blooming (photo by Kate St. John)

The gelatinous fruiting body of Witches Butter fungus (Tremella mesenterica) feels greasy or slimy when damp.  Eeeewwwww!

Witches butter fungus (photo by Gerald Holmes, Valent USA Corporation, Bugwood.org)

Witches brooms in hackberry trees are ugly but don’t kill the tree.  They’re so common in hackberries that I use them as a clue to identify the tree in winter.

 (photo by Whitney Cranshaw, Colorado State University, Bugwood.org)

(photo credits embedded above)

October Scenes from Schenley Park

Phenology, Plants & Fungi, Schenley Park, Trees


The weather was beautiful last Saturday when I took these pictures in Schenley Park.  Even my little cell phone camera was able to capture the colors.  Here are buckeye leaves turning yellow at eye level.

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Blue sky peeks through the trees.

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Golden leaves and green.  The green leaves are porcelainberry.

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The trails were flooded with light.

(photos by Kate St. John)

Porcelain

Plants & Fungi, Schenley Park

With berries this beautiful no wonder this plant was imported.

Porcelainberry (Ampelopsis brevipedunculata) is native to China, Korea, Japan and far eastern Russia.  Brought to the U.S. as an ornamental in the 1870’s it grows so well that it’s now invasive in Pennsylvania.  You can find it easily in Pittsburgh, draped over hillsides and all the trees in its path.

Porcelainberry resembles grapevine except that its stem pith is white, its bark doesn’t peel, and its berries are stunningly beautiful in turquoise, blue and pink.  Birds eat the berries and give the seeds a free ride.

Do nothing and you’ll soon have porcelainberry in your garden.

Want to see it up close?  Visit Schenley, Frick or Riverview Parks.

The berries are worth it, though the vine is not.

 

(photo by Jonathan Nadle)