Sunday, February 21, 2010

Winter ID Workshop

I just spent an enjoyable day at a winter plant id workshop at the Virginia Institue for Marine Science in Gloucester. About 50 people attended the workshop which was led by Doug DeBerry, Senior Environmental Scientist at VHB and Assistant Research Assistant of Environmental Science and Policy at W&M (pictured above) and Jim Perry, VIMS Professor of Marine Science. The event was hosted by the Virginia Association of Wetland Professionals, in cooperation with the Chesapeake Bay National Estuarine National Research Reserve in Virginia.

Dr. DeBerry started the day off with a lecture in Watermen's Hall reviewing some basic concepts of plant structures including buds, leaf scars and stipules. Then we got an overview of herbaceous plants, followed by woody species. The main concepts of what Dr. DeBerry called 'botanical forensics' for herbaceous plants were:

Life Cycle - annual, bienniel, or perennial
Gestalt - the over look of a plant including things like size, shape and odor
Fruit - sometimes an immediate giveaway, sometimes difficult to recognize
Leaves - opposite, alternate or whorled
Stem - hollow, solid or chambered
Habitat - what kind of environment is it growing in?

Included in the price of the workshop was the guidebook Woody Plants in Winter. Dr. DeBerry also recommended Wildflowers in Winter, which includes nice line drawings of herbaceous plants in winter.
In the afternoon we had a hands-on lab to identify 24 species of trees and shrubs. Things like sweetbay magnolia, sycamore, and red maple were easy—I was able to identify about half the specimens on sight. Trickier plants included persimmon, sourwood, and ironwood.
Dr. Perry gives some advice
Examining specimens
Dr. DeBerry reveals the answers

For the plants I didn't know, I had to pull out my new copy of Woody Plants in Winter and work my way through the plant key in the front of the book, and it wasn't always easy to follow. If you don't already know, a plant key is a list of questions about plant characteristics that systematically narrows down the list of possible plants until you arrive at the correct species. At first, it can seem a bit tedious to go through all the questions but with practice you learn where you can skip ahead to save time. Here's an example of the questions you would answer to get to black walnut (with the correct answers in bold).

1. evergreen - go to question 2.
1. deciduous - go to question 31.

31. Leaf and stipule scars lacking, the buds subtended by minute scales - Taxodium
31. Not as above go to 32.

32. Leaf scars opposite or whorled - go to 33.
32. Leaf scars alternate - go to 89.

89. Climbing or scrambling - go to 90.
89. Not climbing - go to 103.

103. Bearing spines or prickles - go to 104.
103. Without spines or prickles - go to 116.

116. Without leaf scars, but with persistent leaf bases - go to 117.
116. With leaf scars - got to 119.

119. Bundle traces distinct, 3 or more in a line - go to 120.
119. Bundle traces one, or many traces scattered or nearly confluent in a line - go to 191.

120. Leaf scars very narrow - go to 121.
120. Leaf scars broader - go to 145.

145. Pith chambered - go to 146.
145. Pith continuous - go to 147.

146. Twigs rather thick; leaf scars large - Juglans, page 61.
146. Twigs slender; leaf scars small - Celtis, page 85.

At this point, the books gives you a choice of two Juglans species: black walnut or butternut. Since it has a notched leaf scar, it must be black walnut. Mission accomplished!
Here are some more pictures of twigs—click on the pictures to find out the species and some of the identifying characteristics.

This workshop was a good experience for me. When I'm identifying plants, I typically look at leaves, fruit, or the overall shape, and I tend to overlook the details of twig structure . But when you do look at these closely, there's a lot of interesting information to learn. Good luck on your id's!


Janet said...

What a great exercise. We were trying to decide upon a green ash or white ash....leaf scar was the was hard.
This is the type of class I would really like.

Skeeter said...

This workshop sounds very informative. I have so many different types of trees on our land. I wish I could ID them all but cannot. I have many different books to assist me but at times I get tired of the flipping back and forth then to the next book only to flip back and forth some more! Very time consuming. I wish someone would come and tell me the trees then I could mark them and learn more about them. We have Pines, Cedar, Poplar, Elm, Dogwood, Hickory and those pesky Sweet Gums but the rest, I am clueless…

How It Grows said...

Skeeter, it does take some practice to identify trees, but it gets easier over time. It sounds like you've named most of them already...

compost in my shoe said...

Reminds me of taxonomy class at Clemson in the middle of winter. Nakedness for days!

zero said...

Hi sir nice job!
I've put some new photos of my plants and i hope you take alook at them on my blog. U know, they are only a few cactus but id like to know more about one of them...In fact i dont know the name of the fifth plant photo. i will be happy if you can help (: