The 70 degree temperatures in northern Indiana today were likely our last taste of summer for quite some time. As I walked the trails on our property after work, most of the plant species that I couldn't wait to see flowering just a few short months ago were long gone, dormant until the winter doldrums are once again melted away by vernal verses. Only a few hardy species are still in flower.
Showing posts with label Taraxacum. Show all posts
Showing posts with label Taraxacum. Show all posts
Wednesday, October 21, 2009
Monday, June 1, 2009
Just a Dandelion?
Justin and I spent a few hours botanizing together at Indiana Dunes National Lakeshore on Sunday. I took Justin to a sand blowout where I knew that the Federally Threatened Cirsium pitcheri grew, and we saw several plants in flower.
We then began heading back into black oak savanna when we noticed a dandelion. I mentioned to Justin that there was another dandelion in the Chicago Region that I'd never seen, but that I wasn't sure how to distintuish it from Taraxacum officinale. Consulting Plants of the Chicago Region right there in the field, I read the key as Justin examined the plant. Conincidentally enough, we were staring at a new plant for both of us, Taraxacum laevigatum (=T. erythrospermum), the red-seeded dandelion. I bet you've never seen two seasoned botanists get so excited about a dandelion!
This species differs from our common dandelion in several ways. The terminal lobes of the leaves of T. laevigatum aren't noticably larger than the lateral lobes, while the terminal lobe is larger than the laterals in T. officinale. Also, the lobes on the leaves of T. laevigatum are divided all the way to the midvein, while the terminal lobe of T. officinale is not much divided or is divided only part way to the midvein. If flowers are present, you can tell the two species apart by examining the inner phyllaries, which are mostly flat at the tip in T. officinale and callous-thickened at the tip in T. laevigatum. Finally, the seeds in T. officinale are stramineous to brown, while those in T. laevigatum are deep reddish-brown.
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