Showing posts with label Ramalina farinacea. Show all posts
Showing posts with label Ramalina farinacea. Show all posts

Saturday, April 23, 2022

Ramalina Farinacea


Day 192: Lichens have been around for a long time. Obviously, they were preceded by algae, fungi and yeasts because all three are components of the structures we now call lichens, but they were already well established when herbivorous dinosaurs went looking for snacks. Many lichens reproduce both sexually and asexually, a factor which gives them a distinct leg up as to their survival capabilities. Sexual reproduction draws genetic material from two sources, mingling DNA to form new individuals. Asexual reproduction clones the parent material, i.e., the DNA of the new lichen is the same as that of the original. Ramalina farinacea rarely develops apothecia, the fruiting bodies which contain the spores necessary to sexual reproduction, but the margins of its lobes are often heavily populated with elliptical soralia containing hundreds of soredia, its vegetative clones. The soralia are quite obvious in the photo of a fresh specimen on the left. Can you spot them, still holding thousands of green and viable soredia, on the dried-up specimen on the right? Although the parent body is dead, it has the potential to live on in copies of itself. Barring a mass extinction of all life on the planet, I'm betting lichens will be around long after H. sap. has died off.

Tuesday, February 11, 2020

The Dotted Line, Ramalina Farinacea


Day 121: At first glance, it's easy to mistake Ramalina farinacea for an Evernia, however close examination will reveal the rather interesting set of features which distinguish it. First of all, both sides are the same colour. Evernia is paler on the reverse. Second, you may see small perforations in the branches, looking very much like they've been holed by beetles. If you confirm both of these characteristics, then it's time to finalize your commitment. If the soralia are marginal (at the edges of the branches), discrete (separated) and elliptical as shown in the inset, you've found the "dotted line" which gives this species its common name. Sign here, and you're done. A similar species, Ramalina subleptocarpha, has longer soralia which continue along the margins almost without interruption.

Saturday, December 28, 2019

Ramalina Farinacea, Sorediate Margins



Day 76: Lichen terminology can be very confusing even for botanists because certain structures have no counterpart in the physiology of vascular plants. My readers will have heard me use the term "soredia/soredium" for a specific type of vegetative propagule generated by some lichens, and they may also recall having read the word "soralia." Soralia are where soredia are produced. They manifest as small patches where the lichen cortex ("skin") has cracked or broken down. The emerging soredia often have a granular appearance and lack any cortex; soredia are one of the parent lichen's means of reproducing. In the inset, you can see the soralia/soredia along the margins of this fine specimen of Ramalina farinacea from Ohop Valley. Many lichens have more than one reproductive strategy to ensure their survival as species. Some are capable of reproducing both sexually and asexually. On the whole, lichens are atonishingly successful in the natural scheme. They were here long before humankind, and unless we pollute them out of existence, they will endure long after evidence of our brief passage has faded from the surface of the Earth.

Wednesday, November 7, 2018

Ramalina Farinacea, "The Dotted Line"


Day 25: Ramalina farinacea's enchanting common name "the dotted line" refers to the numerous soralia found along the margins of its lobes. The second half of the Latin taxonomy should ring a bell in anyone who has ever eaten farina for breakfast, the cereal product marketed under the familiar brand name, "Cream of Wheat." My personal opinion is that Cream of Wheat is only marginally more edible than sand however it is served, and my experience in having been compelled to eat it on rare occasion makes "farinacea" a word I'm unlikely to forget. Funny how those associations are made. This thoroughly farinaceous Ramalina is relatively common in the Pacific Northwest. Some members of the genus have perforate, lacy lobe tips; they may or may not have grit.