Dichotomous Key

Didn’t use a lot of technical terms, but this should still be useable.

A — Trees

>>>B – Tree with needles and cones

A1 — Not Trees

>>>B – Flowers with blue or white petals

>>>>>>C – Flowers with blue petals

>>>>>>C – Flowers with white petals

>>>B1 – Flowers with lots of pistils(?)

>>>>>>C – Pubescent leaves


  1. Thanks, the key works. In a perfect world we would like to make each of the choices parallel. So B1 would need to contrast with Flowers with white or blue petals, so you could choose Flowers lacking petals instead of flowers with lots of pistils (which is true for plant 4). You would need to add the plants to each of your couplets. B – Plant 1, C- plant 3, C1-plant 2, and D (because you have already used C and C1) – plant 4. Plant 4 shows the catkins of a willow, both pistillate catkins (upper left and lower left with lots of pistils lacking petals, and stamens) and staminate catkins (lower right and lower middle, with lots of stamens lacking petals and ovaries). Best, Steffi.

  2. Tracy Christopherson

    I used your key for the Peer Dichotomous Key assignment in Module 3. Indeed it worked and I made it to the plants correctly, but I do have a little feedback. Be careful at step A’, B, C. You forgot to use the prime symbol on the other C and so they had the same symbol. Also, since you broke at B with Flowers w/ Blue or White Petals, you could have made B’ be more of an opposite like, “Flower’s w/o petals.” Possibly even making the stop at B. “Flowers with petals.” Lastly, I don’t believe you needed to go any further than B’ Flowers with lots of pistils(?) because it was at that stage that I made it Plant 4.
    Cheers, Tracy

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