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Wednesday, November 16, 2011

1: American Sycamore

Hi all!

I sincerely apologize for the delay! Well...it's time for our first tree! Envirothon team...meet the American Sycamore.

Common name: American Sycamore
Scientific name: Platanus occidentalis
Family: Plantanaceae

An American Sycamore on the Drillfield at Virginia Tech.
Some examples of sycamore leaves. Note the enlarged end of the petiole.


"Camouflaged" bark

The bark of the sycamore is thin, a grey-brown, and comes off easily

The green hanging "balls" are the fruits of the sycamore tree.

Another sycamore on the Drillfield.

A better example of sycamore bark.


Up close and personal with the sycamore fruit.

Sycamore twig. Notice the buds.

Another sycamore twig. Notice that at the end (look to the right), the terminal bud is absent because it is enclosed by the base of the petiole.
Form and Size: The sycamore is a large tree and will usually reach a size of 80-100 feet with a diameter of 3-4 feet. It has a large, straight trunk with branches that look spread out or "crooked". This species is well-known for having a large trunk diameter.
Habitat: Sycamores are generally found in wet areas and lowlands, and often by rivers or streams.
Leaves: The leaves are alternate, simple, and palmately veined. They have three to five lobes (separated by shallow sinuses) with toothed margins, and are usually 4-8 inches long. The bottom of the petiole is enlarged and hollow, containing the terminal bud. Leaves sometimes have fuzz or fine hairs on the underside, usually near the veins.
Flowers: The flowers are small and in clusters, with one cluster per stalk.
Fruit: The fruit is a dense ball of winged seeds that may be hard, prickly and green to soft and brown. The seeds mature in fall and disperse in winter.
Twig: The twig has a zig-zag shape, and is orange to brown-colored. Lateral buds that are on the twig are each covered by a single triangular cap.

Bark: The bark is very distinctive, being splotchy or "camouflaged". The thin brown bark comes off easily, revealing white under-bark. 

One of the things I like about tree identification is that there is always at least one distinguishing feature for each tree you meet. The top things that I would use to identify the sycamore would be its size, bark, leaves, buds, and fruits.


New vocabulary:
alternate: The leaves and buds are arranged alternately along a twig (vs. opposite).
simple: The leaf consists of one part, and is not made of multiple blades (vs. compound).
palmately veined: The veins of the leaf are arranged like the palm of a hand (vs. pinnate).
lobes: Sections of the leaf that protrude from the main part.   
margins: Outside edges of the leaf.
petiole: The stem that the leaf uses to connect to the twig.
terminal bud: The flower or leaf bud(s) found at the end of the twig.
lateral bud:The flower or leaf bud(s) found on the sides of the twig.
sinuses: dips in between the lobes of leaves.


Sources used: (I would say that 1 and 3 are the most helpful!)
1. Common Native Trees of Virginia by the Virginia Department of Forestry, 2010 Edition (Book)
2. Eastern Trees by George A. Petrides and Janet Wehr, Peterson Field Guide Series, 1998 (Book)
3. VT Dendrology: Sycamore Factsheet
4. Textbook of Dendrology by William M. Harrow, et al., 8th edition, 1996, Mc-Graw-Hill, Inc. (Book)


P.S. Sycamore flowers aren't out this time of year, so here's a picture: Sycamore Flowers

Saturday, November 5, 2011

A Few Notes Before We Start...

Hi all!

Here are a few notes before we start identifying our first tree!

1. When out identifying, it's a good idea to bring a few tools with you. One of the most important is a field guide.

You can get these at any bookstore or library. Be sure to get something specific, like "A Guide to Eastern Trees of the U.S." vs. "A Guide to Trees of the World" (that'd be a HUGE book).

The other most important tool is none other than...your brain! :)

I know Envirothon competitions don't allow these, but hand lenses and pocket knives are quite useful in identifying trees, especially if you've narrowed down the options to two or three species! A hand lens is just like a magnifying glass, and it's important in finding very small identifiers like pubescence (fine hairs) on a leaf or twig. A pocket knife can be used to cut into parts of the tree, like the bark or twigs. Even if competition doesn't allow these, I'd recommend using them if you are especially curious about trees. I will be using a hand lens and a pocket knife from time to time.

2. I will be posting pictures that I've taken for the trees we're looking at. So, for most of the time, the pictures are mine. If it isn't, I'll give a photo credit for it. Also, I don't own a fancy camera, so I apologize in advance for the quality of the pictures. They won't be beautiful, but I hope that you find them helpful. I will also do my best to cite sources that I've used for each tree, so that you can find these and use them if you'd like.

3. We'll be jumping right into identifying tree species, so I will do my best to define any unfamiliar terminology as we go. If you want a primer to terminology (such as pinnate vs. palmate), any good field guide will have an introduction with these sorts of things in them. "Common Trees of Virginia" also has this.

4. Make sure you have permission (or don't need it) if you need to take off leaves, twigs, flowers, etc. off of a tree.

Our first tree is coming up soon! I will probably post it up tomorrow or Monday at the latest.

EDIT: Ok, it's Monday, and the tree isn't up yet. Please be patient, it'll be up by the end of this week. (3:41 PM, 11/7/11)

--Zoe

Thursday, November 3, 2011

Welcome!

Dear AHS Envirothon Team,

Welcome to the Virginia Tree Blog! I created this blog because I remember having difficulty identifying trees when I was in Envirothon. Now that I'm almost done with a Dendrology (study of trees) Lab here at Virginia Tech, I feel pretty confident that I can help you all out with tree identification. However, I am by no means a Dendro expert. This is why, in addition to my blog posts, I'll include Useful Links (look to your right!) that can help you.

So, how exactly is this blog going to work?

Well, every week or so, I'll post up information about a new tree with pictures to go along with it. You should look at the post to help you learn the tree. I would also recommend going out into the wilderness and finding a real specimen to practice on. Practice makes perfect, or as a fortune cookie once told me, "Repetition is the mother of skill". And this tenet of Chinese wisdom definitely applies to tree identifying!

That's it for now! Please be sure to leave questions, comments, and suggestions for improvement by "commenting" on a post. I hope you all are as excited as I am!

Sincerely,
--Zoe

P.S. We will be identifying most of the trees that are in "Common Native Trees of Virginia", a publication by the Virginia Department of Forestry. You can download the pdf file here: Common Native Trees of Virginia