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These are creative but not necesarily perfect examples. These may not have earned a perfect score but exemplify the nature of the assignment.

Material to accompany labs 1-14

Lab #1 video clips Download Lab 1
First Unknown Dichotomous Keys for labs 2-4 (Printable Version. These links will take you to a printable form of the dichotomous keys. It is in PDF format, if you do not have Acrobat Reader please go to www.adobe.com)

Material to accompany labs 15-28

Dichotomous Keys (Printable Version. This link will take you to a printable form of the dichotomous keys. It is in PDF format, if you do not have Acrobat Reader please go to www.adobe.com)

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Rachel Watson, M.S.
AG 5010
766-3524
Cell: 307-314-9636
rwatson@uwyo.edu

Dichotomous key

A dichotomous key is guide, sort of like a map of characteristics, to lead the user to the correct identification of the plant. The word dichotomous comes from two Greek words that mean divide in two parts. To make a dichotomous key you will choose physical characteristics that can be used to divide a collection into two parts. Possible physical characteristics to use include plant size, plant shape, leaf shape, stem type, color, and presence of seeds, fruits or flowers. You will continue to divide each group in two until all of the groups have only one member.

Our Two Point Insect Dichotomous Key can assist in identifying between an insect and a spider. Beginning with Question #1, determine which statement ('a' or 'b') is true for the insect in question. From there, simply follow the directions at the end of the true statement until you arrive at your identification destination.

NOTE: this key is a bit different from the traditional dichotomous key; I've based it on how I think I make IDs myself, at least in the early stages. It does not cover all genera listed in the 'Freshwater Algal Flora of the British Isles', only more common ones, and mainly ones I have images of.
Tap diagram to zoom and pan. Editable dichotomous key template to create dichotomous key online. Edit this using our dichotomous key maker and easily determine the identity of natural world like animals, trees, etc. You can edit this template and create your own diagram. Creately diagrams can be exported and added to Word, PPT (powerpoint), Excel, Visio or any other document.

How to do it

Step 1: Begin by gathering your plants (or pictures of plants) to be identified. For example: a corn plant, hosta, oak tree and dandelion.

Make A Dichotomous Key Generator Online

Step 2: Decide how to split your group in two parts. Carefully observe your specimens to pick a characteristic which can be used to decide which plant goes into which group. Record the chosen characteristic and the groups formed. For example, this group of corn, hosta, oak tree and dandelion could be divided by leaf color:

A. The leaves are solid green. See #2.

B. The leaves have a white margin. Your plant is a hosta.

Step 3: After the collection has been divided into two groups, divide the first group (group A) into two more groups based on one characteristic. Record your characteristic and groups. When you form a group with only one plant, name it. The next division in this example is leaf edge:

A. The leaves have a straight edge. Your plant is corn.

B. The leaves have a curvy edge. See #3.

Step 4: Continue to identify characteristics and divide groups until all of the plants are named. Be sure to record each division made. When the first group is complete, repeat the steps until all of the plants in the second group (group B) have been named. Your completed key should look something like this:

Make A Dichotomous Key Generator Free

A. The leaves are solid green. See #2.

B. The leaves have a white margin. Your plant is a hosta.

A. The leaves have a straight edge. Your plant is corn.

B. The leaves have a curvy edge. See #3.

A. The plant has a woody stem. Your plant is an oak tree.

B. The plant has soft stems. Your plant is a dandelion.

The sample key is fairly short and simple. The more items your beginning collection has, the longer your key will be. Have a friend try out your completed key to see that it leads users to the correct choices and identification.

A dichotomous key is a useful classification tool that notes the similarities and differences between different plant species. By observing similarities and differences in plants, scientists can classify plants into families and gain further understanding of their characteristics. Scientists use dichotomous keys to organize and classify large amounts of information so it can be easily shared with other scientists and studied.Dichotomous keys can be developed to identify anything.

Online Dichotomous Key

Source: www.brighthubeducation.com

GoBotany.NewEnglandWild.org. Plant Dichotomous Key

Dichotomous Key Worksheet Pdf

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