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In a system like that of Linnaeus, a plant with 5 stamens goes into one group and a plant with 10…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
In a system like that of Linnaeus, a plant with stamens goes into one group and a plant with stamens into another. Two plants of the pea family have stamens, and so does a plant of a quite different family.
- Where would this system put the three plants?
- What is wrong with the result, and what would a natural system look at instead?
Need a reminder? The key ideaShow
Artificial systems used a few superficial characters, such as the number of stamens (Linnaeus), and gave vegetative and sexual characters equal weight. Natural systems (Bentham and Hooker) used many external and internal features. Phylogenetic systems follow evolution. Numerical taxonomy scores all characters with equal weight; cytotaxonomy uses chromosomes; chemotaxonomy uses chemicals.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The grouping. All three plants have stamens, so the system puts them in the same group.
Step 2. The problem. The third plant is not related to the other two. One character cannot show relationship. The system is artificial.
Step 3. A natural system would compare many characters: the form of the flower and fruit, the anatomy, the embryo and the chemicals. These would separate the third plant.
Answer: One group for all three; it joins unrelated plants because it uses only one character, while a natural system uses many.
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