Dichotomous Key
Comments
5 responses to “Dichotomous Key”
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Hi Erik!
I really like your key. It’s simple, straightforward, and easy to follow. I appreciated the indentations as that made which couplet to proceed to much clearer. I was able to successfully key out all of the plants without any confusion.
With that said, I do think a couple things could be improved. Your first couplet (“plants with cones, plants with flowers”) would be easier to understand if both statements were complete opposites – e.g. “plant with cones; plant lacking cones.” Essentially, your A couplet lacks a mutually exclusive statement. This is contrasted by your B couplet, which is mutually exclusive as one plant cannot both have and lack a corolla. Another example, as in the Hulten violet key: “plant with basal runners; plant lacking basal runners” – two dichotomous statements. I do find your A couplet to be completely understandable nonetheless.My last observation is rather nit-picky, but I think that having all of the resolutions (e.g. plant 1, plant 2, etc) lined up with the last characters ending on the same column would improve the appearance and readability of your key. In the violet keys provided for this assignment (the Hulten and Cody keys), all of the resolutions end on the same column, so it looks more organized and is thus slightly easier to follow. Achieving this would simply entail adding more dashes as needed so they all line up.
Overall, your key is very nice! I really appreciate that you didn’t overcomplicate it. Also, I struggled with the same problems when I was making my key.
~ Peer Dichotomous Key Assignment ~
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Hi Erik –
That works! Really well, too. I wouldn’t have thought to say corolla myself, but it’s absolutely correct.
Great job!!
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Hey Erik!
This Dichotomous Key looks great! I liked that you used corolla rather than petals, given the scientific nature of this class (I didn’t do that, haha). You also clearly indicated which couplet to refer to when the descriptor does not describe a specific plant. I was easily able to determine the difference between the 4 plants provided.The only thing that I would change is couplet A and A’. Although it is true that the photos provided show cones, it may be more descriptive overall to say that the leaf structures are needles, so that even plants without cones can be identified by this key. Good job!
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Sable – great feedback!
The reasons I gave preference to cones rather than needles for this exercise is, 1) in Couplet A, cones and flowers are both reproductive features (one for gymnosperms, the other for angiosperms), and 2) needles are leaves, so the couplet would need to be some iteration of “Plant has needles” and “Plant lacks needles”. “Plant has cones” and “Plant lacks cones” is also an obvious couplet to construct.
In this exercise, we only need to deal with the 4 plants in the photos – something *I* have to remind myself about every once in a while (like, almost every time…)! That’s why “Plants have cones” should be coupled with “Plants lack cones” – since some gymnosperms have arils or strobili (and I’m sure other things as well)! I keep having to remind myself to keep it simple!!
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Erik, you have another reviewer. Isabella tried, but the system keeps insisting her review is “pending approval” – and I have no way to move it on. So, she sent me a screen shot and I’m posting it for her. I thought you’d like to see it.
Cheers,
Steph
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