Showing posts with label glossary. Show all posts
Showing posts with label glossary. Show all posts

Saturday, December 12, 2015

Peltigera Membranacea, Membranous Dog-Lichen



Day 60: In yesterday's post, I mentioned the rhizines which appear on the underside of Peltigera membranacea's "leaves" (the thallus). These brown structures are its apothecia, the fruiting bodies which produce the lichen's spores. Their resemblance to badly ingrown toenails is one of the defining characteristics of the species. Other Peltigeras produce similar apothecia at the tips of their lobes, but none is so markedly curled as that of Membranous Dog-Lichen. Why "dog?" I honestly don't know, unless it is because they are lightly furry. The Peltigeras are divided into two groups. "Dog-lichens" exhibit a tomentum (fuzziness) on the upper surface (refer to yesterday's glossary) and "Pelt lichens" which are either shiny or rough (scabrose). To further confuse matters, the Peltigeras are often referred to generically as "the Pelts."

Friday, December 11, 2015

Nesting Nidula


Day 59: One day I returned a little late to the office after a lunchtime walk and was explaining to Kevin that I had been sidetracked by a specimen of Hemitomes congestum while searching for Drosera rotundifolia, blathering on about the uniqueness of the find and the proliferation of mycoheterotrophic species I had been observing through the months of spring, only to have him say, "Crow, I have no idea what you're talking about." It pulled me up short and made me see that while I was throwing around botanical names and terms as casually as if I had been talking about Fred and George, most people are a bit uncomfortable with scientific jargon. I realize now that it might be easier on my readers if I provided a glossary, so let me give you one to accompany this photo of one of my favourite fungi, Nidula niveotomentosa, aka "Bird's-Nest Fungus."

Very often, the Latin name of a species will tell you something about its characteristics. In this case, "-tomentosa" refers to the presence of a tomentum, a velvety or woolly texture found on the surface of a plant. The view through the microscope at the top left shows this attribute...a fuzzy-wuzzy nest for the "eggs" which give this family of fungi its common name. The "eggs" (shown in the nest in the center 'scope view) are called peridioles. These contain spores. The bottom 'scope view shows the peridioles liberated from the "cup," appropriately called a peridium.

On the right, you can see the Bird's-Nests in situ alongside a flourishing colony of Peltigera membranacea, a member of the family of Pelt lichens. The translucent structures which appear like stalactites on the underside of the "leaf" are rhizines, a root-like structure which attaches the lichen to its substrate of rock, wood or soil. If you think fungus-jive is hard to wrap your tongue around, lichen terminology is another breed of cat. We'll get to that in future posts.