Peer Dichotomous Key (forgive me)…

Donaldson: Peer Dichotomous Key

Biol 195 Summer 19


  1. Plants with flowers:
  2. Single flower on each stem:   #3

B’.    Multiple flowers on each stem:

  1. Flowers with petals:   #2

C’.    Flowers without petals: #4

  1. A.  Plants lacking flowers: #1
  2. Leaves are needles: #1


Where does the pine cone fit in this?   How is it accounted for using this?   Asking for a friend 😉

One comment

  1. Craig,
    a little scrambled, but the general idea is there.

    You have to think about two-way choices, go one way, the rest of the plants have to fit into the other choice. So 1. Plants with flowers, 1′ would be plants lacking flowers -> Plant 1 (that includes all images in that bin, needles, spruce cones, etc.), plants with flowers can be further divided into those with A. Single flower on a stem -> plant 3, and A’ Multiple flowers on a stem. Under the multiple flowers on a stem you can make a two-way choice again. B. Plants with petals -> plant 2 and B’ plants lacking petals -> plant 4.

    All the images in one plate are considered a single plant, so there are only 4 plants and thus they only need to come out once in the key.

    Best, Steffi.

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