Friday, March 20, 2009
Edward Tuckerman, the man for whom Tuckerman’s Ravine is named, was an expert in lichens. He spent a lot of time in the mid 1800s collecting alpine plants and lichens in the
White Mountains. He died on the ides of March 123 years ago, but not before contributing much to the body of knowledge on lichens. This week’s topic is Tuckermanopsis americana, one of the 12 species in the genus bearing his name. The suffix –opsis is from the Greek and means “appearance, sight, or view.” In biological naming it has come to mean “resembling.” I have seen a photo of Edward Tuckerman and I can’t say that I see the resemblance. It does resemble other lichens which he collected and described. There is another genus, Tuckermanella, named for him and also a species in yet another genus, Platismatia tuckermanii. Mr Tuckerman was born in Boston, had a law degree from Harvard, and for a short while was a professor of history at Amherst College. He had to stop teaching due to profound hearing loss. He resembled his lichen namesakes in terms of hearing acuity.
When and where found: I found two nice samples of Tuckermanopsis americana on the path in the Greenough Land, one of them on March 15 and the other about two weeks earlier. They had fallen from the trees. You can find lichens all year round but now as the snow melts on the paths in the woods, there is a higher than usual concentration of sticks that have fallen in winter storms and many of these are lichen-laden. There is also some Tuckermanopsis sharing my neighbor’s wooden rail fence with dozens of lichens of many different species.
Identifying characteristics: This is a foliose lichen meaning that it has leaf-like lobes with a distinct upper and lower surface. Many foliose lichens lie fairly flat on their substrate. This one is distinctive because it is more erect. It looks like a tiny version of some frilly salad greens. A healthy sample can be about three inches across. If you look closely you will see little black protusions along the edges of the lobes. These are spore-producing structures called pycnidia. In some lichens the pycnidia are embedded but here they are in somber rows like a line of people at a failed bank. The lower surface of the lobes is pale and wrinkled. Lichenologists are trying to assign common names to lichens. All members of the genus Tuckermanopsis are called Wrinkle-lichens or sometimes Ruffle-lichens. This one in particular is the Fringed Wrinkle-lichen where the fringe refers to the rows of pycnidia on the lobe margins. Finally, to confirm the identity of this lichen, a chemical test and a UV light test are necessary because there is another lichen (Tuckermanopsis ciliaris) with identical appearance but different chemistry.
Remembering Edward: If you are one of those people who ski Tux or you just like to hike in the White Mountains, spare a thought for Edward, the lichen-loving lawyer.
References: Lichens of North America, by Brodo, Sharnoff and Sharnoff; Macrolichens of New England, James W. Hinds and Patricia L. Hinds.
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