Dichotomous Key – SLC

Here’s my Dichotomous Key drawn out in my field sketchbook. It was a bit of challenge for me to think in such a linear way. It seems I like to note the differences in the plants in a bit of a jumble and this exercise kind of forced me to really focus on each difference in their morphology.


  1. The key works Sara,
    always remember that you want to create mutually exclusive choices with each couplet. So if you take care of plant 1 with needles, all other plants have leaves. The second choice was elliptic (entire) leaves vs. other leaf shapes, so here you take care of plant 4 (willow) and the remaining two plants are plants 2 and 3. You do not need to bring plant 4 back into the mix later on as it is already taken care of. So now you will need a character that separates plant 2 and 3, one has white petals (plant 2) and one has purple petals (plant 3). It is nice to use more than one character per couplet. So you could have used few stamens (6) in plant 2 vs. numerous (>10 stamens) in plant 3 or the number of petals for each. But for this exercise one character per couplet is o.k. Some people make a table and tabulate the obvious characters and then you can create your couplets more easily.

  2. Louise Smith

    Hi Sara, I liked your key and think it worked well it was a bit tricky to understand some of your hand writing. It might have been easier to understand if it was typed instead.

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