Six Degrees Of Separation

Day 23: Six degrees of separation: the idea that any two people are but six steps away from one another in the social sphere. Back in the days when my interest in lichens was in an early phase, I discovered a strange mass of tube-like branches, black on the underside, but more notably, bearing several disk-like structures (apothecia) of a rather sickly-looking chartreuse hue. I had discovered my first Hypogymnia. With my curiosity for the genus piqued, I began looking for other species within it, learning to identify them from the way they branched, the colour of their medullary ceiling and other cues. I developed a particular fondness for H. imshaugii (above), partly because it was present in my yard and partly because I was curious about the person after whom it must have been named, so I dug a little deeper and came up with a Wikipedia article about Henry Andrew Imshaug who, it must be confessed, should have been on my radar as a notable lichenologist. However, it was some time later when H. Imshaug the botanist (as opposed to H. imshaugii the lichen) came to the forefront of my attention when I found out that he was part of an expedition to inventory the fungi of Mount Rainier National Park in 1941. During that survey, he and his colleagues discovered a rare fungal species and wrote a paper about it. My botany partners and I learned of Imshaug's paper when we stumbled across the same fungus, although in a different area. Imshaug didn't have access to GPS technology in 1941, so his description of the location where he had found it was vague to say the least, but armed with knowledge of the fungus' preferred host and a rough idea of where Imshaug's group had gone, we were able to locate the site. Standing there among sedge and tinker's-penny, I thought about H. Imshaug the botanist, and how H. imshaugii the lichen had been instrumental in piloting me to the same ground where he and his team had stood. The six degrees of separation had come full circle for Imshaug and me.

Hypogymnia Imshaugii

Day 41: Henry Imshaug lent his name to one genus and several species of lichen, including some which occur here in the Pacific Northwest.In 1941, Professor Imshaug and several of his colleagues performed mycological surveys in Mount Rainier National Park, noting at least one rare species of fungus which I have also had the privilege of observing. In fact, my botany partners and I were able to locate the site where Imshaug made his discovery and documented the species' current existence in the same location. Is it any wonder that Hypogymnia imshaugii has become one of my favourites because it bears his name? Also known as Forked Tube for its neatly branched lobes, it is relatively easy to identify if one of the puffy tubes is opened. The medullary ceiling (underside of the top layer) is white, distinguishing it from similar H. inactiva.

Hypogymnia Imshaugii

Day 130: The Hypogymnias are collectively known as "tube lichens" for reasons which become obvious if you look at them closely. Their lobes appear inflated and in fact are hollow. The upper surface is greyish-green, separated by a distinct dividing line from the black lower surface. The apothecia are generally large when present, making the genus fairly easy to identify in the field. Determining species gets a little trickier, but H. imshaugii (Forked Tube) has a characteristic which sets it apart from its look-alikes. If you pull one of imshaugii's slender lobes apart to examine the inside, it will reveal a white medullary ceiling, which is to say that the inside of the top side is white. H. heterophylla, H. inactiva and H. enteromorpha all have black or dark medullary ceilings. Other species of Hypogymnia may have broader lobes, pinched lobes, holes at the lobe tips. These are all features to take into consideration when trying to identify them.

Hypogymnia Imshaugii, Forked Tube Lichen

Day 7: I keep falling over the name "Imshaug" in my travels, sometimes attached to lichen taxonomy, other times to research papers or field studies. Although I'm not normally the least bit interested in human history, Imshaug's repetitive presence raised my curiosity. I haven't been able to find out much about him, since it seems that academics are as proprietary about biographical information as they are about scientific discoveries, but what I have been able to find without paying $10 for the privilege of reading a 7-page article is that he was primarily a lichenologist and was the curator of the cryptogam collection at Michigan State University's herbarium. Bingo! That answered one of my main questions right there. Imshaug's name appears in the list of explorers who, in 1941, found Myriosclerotinia caricis-ampullaceae in Mount Rainier National Park, a rare fungus which captured my attention several years back. I wondered how an herbarium specimen of the rare cup fungus cropped up in MSU's collection. Imshaug undoubtedly took one back with him. Imshaug oversaw the studies of a number of graduate students who went on to become noted lichenologists themselves, including Irwin Brodo, author of the forty-pound field guide, "Lichens of North America." The lichen shown above also bears his name: Hypogymnia imshaugii, Forked Tube Lichen.

Sorting Out Hypogymnia

Day 138: Well! That came as a bit of a surprise! I have several Hypogymnias occupying my fence rails and had identified H. inactiva and H. pinnata previously by examining the inside of the tubular thallus. As a group, the Hypogymnias are known by the common name "tube lichens," referring to their hollow structure. Most are black on the reverse and have various degrees of black speckling on the front; some have tubes which are open at the ends, and some fork in distinctive manners. All these characteristics help separate them by species, but when it comes to the trio of inactiva, pinnata and imshaugii, surgery is required to reveal the medullary ceiling. Inactiva's ceiling is black. Pinnata's is dark, and therefore the two can be confused. However, imshaugii's medullary ceiling is white (circular inset). I'm glad I checked! And thus a new name has been conferred upon part of my garden: the Imshaugii Rail.

Hypogymnia Imshaugii, Forked Tube Lichen

Day 131: The Hypogymnias are abundant in my area (even in my own yard) and more than one species frequently occurs on the same branch. Forked Tube has a couple of look-alikes, but these can be sorted out fairly easily by opening one of the "tubes" which give this family its common name. Hypogymnia imshaugii has a white medullary ceiling, clearly visible in the broken tube just left of the two apothecia on the right, less distinct in the tube in the "ten o'clock" position left of the largest apothecium. Both H. inactiva and H. heterophylla have a black/dark ceiling. H. inactiva generally shows more black as well, often extending into the upper surface from the underside of the thallus. H. heterophylla is not as regularly branched.

Needless to say, I didn't get much done in the way of yard cleanup today, what with damp weather and a whole raft of lichens brought down during the winter storms. Priorities...it's all about priorities.