Photographic Atlas #2: Barnyard Grass

As I walk through our parks I am struck at how many things there are that I can’t give a name to! That’s the genesis of this blog series. If I start to learn some of these things, why not share them with the readers of this series? The group (or taxon) that gives me the most trouble is the grasses. They all look the same! And as you walk through your parks, you may notice as I have that there are plenty of similar-looking grasses.

Grasses do look a lot alike, so taxonomists use diagnostic characteristics to tell them apart. Those are distinguishing characteristics, like a certain color in a certain part of the grass or a certain type of seed. But those characteristics won’t make any sense without knowing the parts of a grass. Then one can use what’s called a dichotomous key, which is a tool used to determine the identity of an unknown species by answering a series of questions that are broken down into two choices leading one to the correct species.

And so if you are walking through your parks you may come across the very common grass called barnyard grass (Echinochloa crus-galli (L.) Beauv.) [ECHCG]. Also called panic-grass or watergrass, it is a summer annual that reproduces by seeds that germinate in early spring to mid-summer. It’s part of the Echinochloa crus-galli complex. Taxonomists often include many similar species and varieties into a complex to indicate a high degree of similarity between many species or due to the complexity of the group, but generally it means a group with similar-looking species or varieties.

A closer look at the inflorescence

The distinguishing characteristic of barnyard grass is the inflorescence of its spikelet. It is found along ditches and other areas with moist soil. It’s considered a common weed and grows best with rich soils and so is found in disturbed sites with enriched soils. It doesn’t seem to be a pest plant in our parks. It’s part of the complex of species that live along the trails and streams.

Many grasses make up the species of our parks and play very fascinating, complex, and unknown roles. They provide forage for small mammals and mulch after winter has killed them.  See the bottom of this post for a quick guide to the different parts that make up a grass plant.

Collecting park plants for categorizing.

The roles of all the species in our parks are constantly unfolding before our eyes. As the seasons come and go, the grasses and other plants change in complex and exact manner and sequence.  As you go through the parks, notice how many of the same types of species are in one place. For example, how many species of grasses are in one site versus another site and why? Or how many different species of trees are in one place versus another? Sometimes the answers are obvious–it’s wet or dry, it’s sunny or shady, it’s disturbed or forested. But sometimes it’s baffling!

We have many more plants drying up in the press and will be telling you about more soon. Next up we have ragweed! Many of you know that as the plant that causes hay fever and despise it, but maybe it has some good uses…stay tuned!  And remember if you have a picture of a plant you can’t identify please send me a few pictures and tell me where you saw it and I will try to identify it!

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Photographic Atlas of Plants of Pittsburgh Parks

We’re starting a new series on the blog today called the Photographic Atlas of Plants of Pittsburgh Parks.  Our beautiful parks are biological treasures nested and locked in an urban environment.  The plants and animals are reservoirs of the biological diversity that once existed.  This series will feature those special, unique, and common species that make up the biological fabric of our park ecosystems.  Each post will feature a different species, discussing where it lives, how and why it was collected, and how you can have your own sustainable collections.

Today’s blog will discuss the ethics of plant collection.  Subsequent blogs will feature individual plants and animals.  To nominate a species to be featured (or identified) in this series, send an e-mail with a photograph and whatever information you have to bdolney@pittsburghparks.org.

Introduction to Plant Identification

A plant identification toolkit.

The Chinese philosopher Krishtalka said, many centuries ago, “The beginning of wisdom is calling things by their right names.”  This in a nutshell is what taxonomy–the branch of biology that deals with naming and classifying biological species–is all about.  Before ecologists and conservation biologists can move in and work at conservation, restoration, or preservation of a park or reserve, they must first know what stuff lives there.  This is why taxonomy is so important; it lays the foundation for good biological and ecological decision-making.

So this blog series will deal with the naming and counting of the species of our four regional parks.  Traditionally, plant taxonomists do their collecting in the spring and early summer when plants are blooming and most other diagnostic characteristics are present.  Then in the winter, when field work is not possible, they can be identified.  So shall we, for a few of our most common species, collect, dry, and mount them for you–to see the process from beginning to end.

When collecting, it’s important to get several specimens of each species, trying to get as many flowering parts as possible, including all shoots and roots.  Back at home, they can be pressed in a plant press until they are dried.  Next, they are arranged to display all the characteristics and flowering parts, and glued to herbarium paper.  Finally, a label is attached to the lower corner of the paper, and they can be filed away for future reference.

For the vast majority of the species we profile, we will take pictures in the field and report here what we have found, following the motto, “Take nothing but pictures, leave nothing but footprints.”  For those of you interested in starting your own plant collection, I suggest a digital camera.  It’s also important to remember that all plants and animals in the parks are protected and they cannot be removed or harmed.  The collection of biological material from any public land should only be done if there is a very good reason and only then when the species are abundant (never rare or endangered species).  Usually, collections are made by researchers who want a record for educational purposes, and only then when there is permission given to do so.

As this series progresses, we will slowly compile a species list, occasionally publishing an updated list.  Please give us your feedback!

Our First Species: Flavoparmelia caperata

Flavoparmelia caperata

A good place to start with this series is to talk about the most prominent and conspicuous species–the ones that are either widely dispersed, very prominent, or really peculiar.  So let’s start with peculiar.  I can think of none more so than the lichens.  Lichens are a symbiotic organism, composed of a fungus and an algae.  They are the fungus-like stuff you see on trees and rocks.

In your parks they are widely dispersed: found on rocks, trees, and various other dead wood.  The species I want to single out, though, is the most prominent one–Flavoparmelia caperata, common green shield lichen.  It is found in most of eastern North America, except for Florida.  It is widely believed that lichens are good indicators of air quality because they acquire all their nutrients and water from the vapor in the air, so when the air is dirty it can cause many of them to die off.  Flavoparmelia caperata is considered to be of this kind.  Before its current use as a bio-indicator, native peoples in Mexico crushed up its dry parts and used the powder to treat burns.

Flavoparmelia caperata can get quite large.  I have seen specimens in our parks almost 10 inches across.  It is pale or yellowish green and loosely attached to whatever it is growing on.  If you tug at it, it will usually come free without much effort.  The rough bumpy wrinkled surface is its reproductive parts, called soredia.  Turn the lichen over and you will see that it is black.  The soredia and its black under surface are diagnostic characteristics (those features that can be used to distinguish it from others).

Once you start looking, you may notice that Flavoparmelia caperata is more common on trees than rocks.  The trees you may see it on include most oaks (especially red oak), black cherry, and tulip poplar, but it can be found on almost all the types of trees in our parks.  And you may also notice that it forms rather large mats covering the entire surface of a tree.  A place to see an example of this is at Frick Park behind the baseball field off of Braddock on the large red oak (N 40°26.231′,W79°53.900′).  Here it covers at least three sides of the tree and stands out quite prominently. 

So next time you are hiking through one of our parks, you can point up and say that’s the lichen Flavoparmelia caperata.  Your hiking partner will be impressed, I promise!

Stay tuned for the next species to be profiled, and if you have any comments or suggestions, please direct them to bdolney@pittsburghparks.org!

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