Keying Exercise (2)

Walk prep: turmeric ginger latte, Mountain & Prairie Podcast, dog, "Trees Among Us" (Ritter).

1. Cook Pine (Araucaria columnaris) - pg. 25
   Keying steps: 1', 2', 3, 4 --> Group 2 (Trees with scale-like, awl-like, or apparently absent leaves) --> 1', 4, 5
   Where I almost went wrong: I forgot that each little "scale" is a leaf, rather than the whole "tassel" or branchlet (step 4). When I got to Group 2, I didn't think the tree was "distinctly columnar" (step 4), but I did think the branchlets were rope-like and saw Auracaria as an option, so I followed that path.

2. Coral Trees (Erythrina spp.) - pg. 26
   Keying steps: 1', 2', 3', 5, 6 --> Group 4 (Trees with palmately compound leaves)--> 1, 2, 3
   Where I almost went wrong: I had trouble deciding how the leaves were attached. I didn't think they were palmately compound (step 6), so I almost went with 6' (leaves pinnately or pinnately compound), but then decided they might be palmately compound, after all.

As mentioned previously, I've used this key before in my landscape architecture classes but I haven't had consistent practice with it, so it can be a bit of a challenge for me each time I pick it up again. I knew the first tree was from the genus Araucaria, so I had a bit of an advantage there, but I had some trouble differentiating the species from similar species. I just knew it definitely wasn't Araucaria bidwillii.

The coral tree was new to me. I thought the phyllotaxy was interesting because the leaflet attachment wasn't like other palmately compound attachments I've seen. I'm still unsure if it's even palmately compound.

Posted on May 13, 2020 05:53 PM by alexmichel