#dailylichenpost

Umbilicaria polyrrhiza

Dactylina madreporiformis (syn. Allocetraria madreporiformis)

This finger-like little friend grows on soil, sand silt, and plant debris in arctic-alpine regions. Think very cold and very windy, far north, or at high elevations. It is apparently widespread throughout the Alps, so I know exactly where I am headed when this lockdown ends! 

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Crocodia aurata

This lichen is gorgeous! I mean, just look at that neon lobe liner. A real statement piece.This foliose member of the Lobariaceae family forms broad, sinuous, undulating lobes 5-15 mm wide. Lobe magins are covered in bright neon-yellow soredia, and lobe tips are covered in thin, hair-like structures. The upper thallus color is bright green when moist, and turns an ashy gray or tan when dry. The lower surface is pale and tomentose, and is often speckled with bright yellow pseudocyphallae. Apothecia are rare, and form submarginal, glabrous discs. C. aurata can be found in temperate, tropical, and suptropical localities where it colonizes trees in humid, open forests. 

Usnea longissima 

Old man’s beard, Methuselah’s beard lichen, bearded lichen, hanging hair

This lichen is on my list of things I wanna see before I die! U. longissima is a fruticose lichen and is the longest lichen in the world! No surprise there. It can grow to be over 30cm long. Besides its shear length, it is characterized by light yellow-green coloration, short side branches along that long stem, and tendency to hang pendulum like down from conifer branches. U. longissima is found growing in boreal and coastal forests in the northern hemisphere, though its range used to be entirely global. Usneas are known to be very nitrogen sensitive, so are only found growing in areas with little air pollution, and populations have been decreasing in recent years because you know, air pollution and deforestation and all the other stuff we are doing to the environment. There are other fruticose lichens that can also look fluffy like this guy, but if you want to know if the beardy lichen near you is an Usnea, give the central stem a gentle tug, and if it feels elastic, you have yourself an Usnea, and if it is longer than you are tall, it is probs definitely U. logissima.

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Crustose: Crusty lichens! Fully attached to the substrate. Usually can’t be removed without damaging the lichen and or the substrate.

Foliose: Leafy lichens! Flat, usually detached from the substrate at various points so that you can see the upper and lower thallus and remove them from their substrate.

Fruticose: Fluffy lichens! They have a tufted or stalked thallus, and it can be difficult to determine an upper and lower surface. Often look like little plants.

Squamulose: Scaly lichens! Thallus made up of small, flat, overlapping units. Not as attached as crustose lichens, but more attached than foliose lichens.

Thallus: The lichen body which contains both the fungal and photobiont (algal or cyanobacterial) components. Cortex: The protective outer wall of the thallus made of specialized fungal hyphae. Lichens can have separate upper and lower cortexes, a wrap-around cortex, a single cortex, or no cortex.

Rhizines: Kinda like the roots of a lichen. Little filaments that protrude out of the bottom of the thallus and attach the lichen to the substrate.

Cilia: Stringy protrusions projecting from the sides or upper surface of the lichen. Different from rhizines.

Photobiont: The symbiotic component of the lichen that performs photosynthesis. An algae or a cyanobacteria.

Podetia: Hollow, stalk-like protrusions of Cladonia lichens  

Apothecia (apothecium): A fruiting (sexually reproducing) structure produced by the fungal component of the lichen. Usually rounded cup which contains fungal spores. Not present on all lichens, but often help with identification. And are very cute.

Perithecium (pl. perithecia): An embedded, flask-shaped ascocarp (fruiting body) in the thallus that releases sexual fungal ascospores. Often only visible from the outside as a small hole or pore.

Isidia (isidium): Small thallus outgrowth that acts as an asexual propagule for lichens, and contain both fungal and algal constituents. They can detach and grow a whole new lichen clone! They have a cortex. 

Soralia and Soredia: Soralia look like cracks in the lichen surface filled with powdery granules (the soredia). Soredia are another asexual propagule and include both mycobiont and photobiont constituents, and they lack a cortex.

Schizidia (schizidium): Scale-like asexual propagules. They have an upper cortex but no lower cortex. 

Macula: small pale spot resulting from a lack of photobiont cells in that area of the thallus. 

Pruina: Powdery deposit of crystalized calcium oxalate, secondary lichen metabolites, or dead fungal cells. Makes the surface of the lichen look frosty or chalky (adj. pruinose).

Cyphella: A recessed pore in the lower thallus surface with a pale rim where fungal hyphae poke through. Round, usually pale, fuzzy-looking spots. 

Pseudocyphellium:  A pore on the lichen thallus surface lacking cortex so medullary hyphae stick out. Lacks a defined rim, can be linear or orbicular. 

Pycnidium (pl. pycnidia): An embedded, round or pear-shaped structure that goes down through the thallus and into the medulla and produces small spores that can either be asexual propagules or spermatia. Appears as a small, dark pore in the lichen surface.

Areolate: A crustose thallus growth form that appears tile-like in appearance. It looks like dried and cracked paint/clay. Each individual section is an areole.

Rimose: A crustose thallus growth form that has cracks, splits, or striations. 

I will continue to edit and add more as needed!

Xanthoria parietina 

Common orange lichen, maritime sunburst lichen, shore lichen   

Starting off with this charismatic pal, X. parietina. Easily recognizable due to its orange, foliose lobes and habit of growing anywhere and everywhere, this species is incredibly tolerant of pollution and human activity, and will probably takeover the world soon. In spite of that obnoxiously neon hue, its photosymbiont is actually green algae. Also, it was first described by Carl Linnaeus, you know, just the father of taxonomy, so that’s pretty cool. 

Graphis scripta

Common script lichen, secret language lichen

There are a host of Graphis lichens to choose from when highlighting this particular genus of script lichens, but I decided to go with the most common species, G. scripta. Well, maybe it is not really the most common. With over 300 very similar looking species, this particular species name may be over subscribed. Like the other members of the Graphidacae family (thought to have the most species of any lichen family), G. scripta is crustose, and lacks a thallus. It is a lightly colored cream or gray, with those distinct lirellate apothicia that give it the appearance of writing. It can also have immersed pycnidia. It prefers to grow on the smooth bark of deciduous trees. As mentioned above, there is some debate on if this particular species is restricted to temperate zones, or if the species concept should be applied to more wide-spread tropical and sub-tropical species. Either way, you are likely to run into a Graphis somewhere out there, so keep your eyes open for this cool lichen pal, and maybe you will decode what it is trying to tell us with its mysterious writings. 

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Cladonia chlorophaea