Dichotomous Key

Gymnosperm…………………………………..Plant 1


  • Petals absent…………………………..Plant 4
  • Petals present
    • 4 petals……………………..Plant 2
    • More than 4 petals………Plant 3


  1. jthumphrey

    Works well. It took me a minute to come up with a good way phrase the difference between the spruce and the other plants, so I like the use of angiosperm vs gymnosperm.

  2. Marcia Anderson

    Hi Derek, I liked the choice of angiosperm vs. gymnosperm in this key. I did make sure I looked them up and used the Merriam-Webster definition so I could use them correctly to try to identify the assigned plants. Our keys are similar, as I used Woody in A. and used Herbaceous in A’, where A. ended with just woody. I think looking at petals present vs. petals absent is smart, and you can break this down further by asking whether the corolla is fused or not, as suggested in the Dichotomous Key Practice on our class website. Then you could continue on with petal color to add. You could also move even further with choosing between ovary inferior or superior, if you wanted to break it down more. You could add more to the Gymnosperm as to whether there was needles present or not and if these leaves were attached singularly or as fasicled leaves (more than two attached). I like simpler the better when I am learning, so really nice job. Marcia

  3. Marcia E Anderson

    In addition, using your Dichotomous Key, the first plant was a gymnosperm. The second plant was an angiosperm with 4 petals. The third plant is an angiosperm with more than 4 petals, and the 4th plant would be with an absence of petals. Marcia

  4. bcbolduc

    Hey Derek, I used your key to help identify the plant specimen in the 4 pictures. Considering it was only 4 pictures it was quite easy especially with present or absent petals. In the future, I might explain what angiosperm (Plant producing seeds enclosed by carpels) or gymnosperm (plant with seeds near an ovary/fruit lacking covering or protection) are if the individual has no prior background knowledge on plants, fortunately since we went over it in class, we hopefully all understand the difference. Aside from that, great key – thank you for sharing.


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