Dichotomous key

A.Plant One:

B. Needles with flat cross section–slightly rounded at the tip, green in colour–some brown spots.

B1. Branchlets glabrous; cones.

B2. Thick, cylindrical bole (trunk)–aereal stem of plant. 

B3. Perennial plant.

A. Plant Two:

C. Flower white in colour.

C1. Rootstock stout; drooping.

C2. Compound plants.

C3. Nodes and internodes.

C4. It has 4 petals.

C5. Raceme.

C6. Flowers sit on pedicels (a pedicel is hairy-looking–pedicel trichomes).

C7. Sepals, stamens-interior (tetradynamous stamens).

C8. Stamens with yellow pollen on tips. 

C9. Whorled.

A. Plant Three:

D. Flower violet in colour, white at the base.

D1. Drooping rootstock stout. 

D2. Plentiful amount of stamens interior to petals. 

D3. Stamens yellow in colour–there appears to be 4.

D4. Several nodes on the stem. 

D5. Pedicel trichomes.

A. Plant Four: 

E. Ericaceae.

E1. Leather-like leaf. 

E2. Outgrowing stamens exposed–yellow and green in colour and red in colour at the base bud of stamens

F. Dissected flower with 2 stamens per bud.

F1. Dissected flower with 3 stamens per bud.

F2. Dissected flower with 4 stamens per bud. 

E3. 22mm length of the entire bud. 

E4. Pedicel trichomes.

E5. Dissected–between 2-4 stamens per bud.

One comment

  1. Donna Levesque

    Natassja, your dichotomous key is very well thought out and impressive! It includes a logical sequence, and specific, botanical terms. I have learned new terms from your key, which is phenomenal. I can easily see and appreciate all the work that you’ve put into creating it, especially because I took a very similar, painstaking approach to mine. (Emphasis on the word pain.) So when Steffi asked that I revise and resubmit my key, the wind went quickly out of my sails. Fortunately, that was before the 4th of July, so I felt okay about putting my key on the back burner. When I returned to the assignment, I read Steffi’s comments much more closely, particularly elements of the key that she suggested toward the end of her reply.

    Somehow, I had missed that our dichotomous key was directed at the four plants as a whole, and not a dichotomous key for each plant individually. (Sound familiar?) Now that I’ve revised my key, which took an eighth of the time, I can chalk my original version up to an exercise in learning all sorts of plant anatomy and vastly improving my botanical vocabulary. All is not lost!

    If you haven’t already done so, I would humbly suggest that you whittle your key down to 10 lines, or fewer, using the first few lines from Steffi’s suggestions to restructure your key. I trust the rest will just roll itself out for you, truly. It may also help to look at others’ keys. They’re all different, but will give you an idea of how to simplify your great work.

    Here’s to simplicity!

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