Lichens
August 19, 2009
Cladonia cristatella
Nebulagirl posted today's Botany Photo of the Day in our Flickr Pool two weeks ago. She included a number of great shots in addition to this close-up, all of which you can access here. Of course, we extend our thanks to nebulagirl for this opportunity to take down and dust off our old lichen-related volumes.
Cladonia cristatella is just one of the planet's over 14000 lichen species. Unlike most plants, lichens are composite organisms; they develop, that is, from a symbiotic association between a unique fungal species and a photosynthetic partner (often green alga or cyanobacteria). They have no hydration apparatus, and this allows them to excel in conditions and habitats fatal to most other plants (deserts, arctic tundra, bare rock and sterile soil). Lichen species' capacity to adapt to the labile complexion of their surrounding environment is perhaps best demonstrated by their ability to enter metabolic suspension (dormancy) in order to survive desiccation in periods of intense water deprivation, proceeding to rehydrate and thrive when a supply of water again becomes available. Though they often grow on other plant specimens, lichens are not parasitic, and they have little, if any, adverse affect upon their host; some species, particularly those in the subgenus Cladina, do, however, emit into the soil chemicals that inhibit, or even preclude, the growth of competing plants. Historically, parts and extracts from lichens have served as ingredients in dyes and perfumes, and they have been thought effective treatments for lung disease and rabies. Generally speaking, humans have not made standard fare of lichens, as most species have a bitter taste and little nutritional value.
In today's photo, Cladonia cristatella (British soldier lichen) seems to ooze from its decaying woody host like fresh magma bubbling up from the coarse veins of the ocean floor. The species joins the Cladonia fungus and the Trebouxia erici alga. A thin stalk lifts the red, club-shaped apothecia up to a height of about 25 mm. This is eastern North America's only red-fruited Cladonia species lacking in both soredia and granules (typical reproductive structures). Unlike other lichen species, Cladonia christatella is somewhat tolerant of pollution, and this is why, in urban areas, it is more common than its relatives.
Source:
Brodo, Irwin, Sylvia Duran Sharnoff, and Stephen Sharnoff. Lichens of North America. New Haven: Yale UP, 2001.
Posted by Stephen Coughlin (summer student 2009) at 7:00 AM| Comments (14)
October 15, 2008
Cladina sp.
I'm on vacation, so please accept my apologies for the brief entries. -- Daniel.
I'm not sure of the identity of this one, but I suspect Cladina rangiferina, or reindeer moss (though it's really a lichen). This was growing at ~850m (2800ft) in elevation. It was a common sight in the White Pass area, although I must admit it does look a bit different when a macro lens is used (see other images of Cladina spp.).
It also seems that all Cladina species are now lumped into Cladonia; the USDA PLANTS database still uses Cladina.
Posted by Daniel Mosquin at 12:00 AM| Comments (9)
December 16, 2007
Bryoria fuscescens
Apologies for the late entries recently – I'm finishing up a big project (that you'll get to see at the end of January or so) and all that goes with that, so opportunities for rest are taken when I can get them.
I'm fairly certain of the identity of this lichen, though it could be another species in the genus. If it is Bryoria fuscescens, its common name is speckled horsehair lichen or pale-footed horsehair lichen. The epithet fuscescens means “becoming dark”. The related Bryoria fremontii is regarded as “the most widely used edible lichen in North America” (see edible horsehair at the Lichens of North America site).
Bryoria fuscescens is widely distributed across North America and Europe, particularly in association with montane and boreal forests. It is commonly found on conifers.
Posted by Daniel Mosquin at 10:46 AM| Comments (5)
August 28, 2007
Verrucaria maura
Thank you to Stephen B of Scotland aka stephenbuchan@Flickr for sharing today's photograph (original). I've been wanting to feature this species for a while, so much appreciated, Stephen!
If asked to create a list of familiar organisms by the seashore (and lived in a temperate area), I'm betting that most people would not include “lichen” on the list. Narrowing it down to a list of the organisms in the intertidal (the band of life between the high-tide and low-tide marks), and I'm still willing to bet lichen would be absent from most lists. Mussels, yes. Barnacles, yes. Seastars, likely. Seaweed, yes. Lichen? Not likely, unless you know that the black patch of what looks like oil residue is not what it first appears to be.
Sea tar or black seaside lichen is found along coastal rocky shores throughout much of the temperate parts of the world. In these areas, it is often a component of the upper intertidal zone and, above that, the salt-spray zone. To give a rather unscientific example of how it is overlooked, its near-constant intertidal companion with a similar distribution range, Mytilus edulis (or blue mussel / common mussel) receives nearly 600 000 hits on a popular search engine; Verrucaria maura? Fewer than a thousand.
The UK-based Field Studies Council has a small article about tar lichens in general, and a specific page about Verrucaria maura as well. Through photographs, Seaweeds of Alaska reveals how Verrucaria maura can be seen from the air. A closer photograph of the banding caused by lichens is displayed in a story about lichen study in the Gwaii Haanas National Park Reserve of British Columbia: Time for Nature – Learning About Lichens.
Posted by Daniel Mosquin at 6:20 AM| Comments (5)
June 24, 2007
Letharia columbiana
Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel
Brown-eyed wolf lichen is considered one of two species in the genus Letharia (the other being Letharia vulpina). At first glance, it is readily distinguished from its counterpart by the presence of brown apothecia. However, read Susanne Altermann's “A Second Look at Letharia (Th. Fr.) Zahlbr” (PDF) from the Winter 2004 Bulletin of the California Lichen Society for information that suggests the classification of species in the genus might be a bit more complicated than at first glance.
Posted by Daniel Mosquin at 12:00 AM| Comments (1)
March 25, 2007
Letharia vulpina
It's been a while since I've shared one of these types of images. Letharia vulpina growing on an old, fallen log of Pinus ponderosa.
Natural history resource link (local): Volker of Surrey, British Columbia recently shared his weblog with me: Haliaeetus. Volker shares his nature and seasonal observations through photography and commentary.
Posted by Daniel Mosquin at 5:52 AM| Comments (5)
February 16, 2007
Lichen Diversity
This is a companion image and written entry to a previous BPotD on lichen diversity, though it was photographed three months earlier and 900 km (~550mi) away from the other image. I was pleased to discover lichen-covered rocks in Grasslands National Park, as it was an unexpected photographic dimension in exploring the area; I'd anticipated the skyscapes, the endangered species and the wildflowers, but not the lichen patterns.
In comparison to the crustose lichen-covered rock in the other entry on lichen diversity, I would expect the process of succession to occur over a much larger time scale. Dessication, temperature extremes, wind abrasion and fewer moss and vascular plant colonizers create conditions where the reign of the lichens is unlikely to be toppled for centuries, if not millenia.
On a different topic, I had the opportunity to walk around the garden for a small time yesterday, and noted that spring is tentatively making an appearance. I imagine 2007 photographs will soon start to become common on BPotD.
Posted by Daniel Mosquin at 6:04 AM| Comments (1)
September 2, 2006
Cladonia spp.
Two folks from British Columbia contributed today's images, both submitted via BPotD Flickr Group Pool. Lotus J., aka ngawangchodron@Flickr submitted the first image (original image) and Brettf@Flickr submitted the second (original image). Thank you to both of you, much appreciated.
Both photographs demonstrate a member of the genus Cladonia, or cup lichens. One of the distinguishing features of Cladonia is a two-part body consisting of primary thalli and podetia. Primary thalli and podetia are present in both images; the thalli are the “flat little crusty green bits” (most of what can be seen in the first photograph, but not as ubiquitous in the second) while the podetia are the stalked structures. The red parts on the end of some of the podetia are apothecia, a particular type of spore-bearing structure.
Identification of Cladonia can be difficult, and I haven't spent a lot of time attempting to identify the one in the second photograph, though it should be possible with the podetia present. Identifying Cladonia before the podetia are developed, however, is difficult beyond recognizing that it is a Cladonia. As Trevor Goward writes in Plants of Coastal British Columbia: “Though easy to recognize as a group, the cladonia scales are notoriously difficult to identify to species. Still, it can be ‘fun’ trying (consult a technical manual such as Thomson 1967).”
Photography resource link: Photography Locations via The Luminous Landscape. Finding where to photograph can be difficult (especially when travelling), so resources like these are very helpful. I only wish such a thing existed for wildflowers, since this resource concentrates on landscapes.
Posted by Daniel Mosquin at 12:00 AM| Comments (3)
February 7, 2006
Hamamelis ×intermedia 'Fireglow' and Evernia prunastri
Updated February 7, 2006 at 4:06pm: Thanks to Doug who suggested some alternatives to my tentative identification in the comments, I went out and re-examined the lichen. I'm now reasonably confident that this is Evernia prunastri and not what I misidentified it as, Platismatia stenophylla. I think it's an opportune time to remind you that I'm more interested in having the correct information available to BPotD readers than I am in being “right”. If I ever post something that doesn't sit right with you or if you can add something (including a different perspective!), please comment – Daniel.
Mysteries abound, today. Let's start with the lichen. I'm fairly certain it is Platismatia stenophylla or ribbon rag lichen, but it's difficult to confirm. I've only one image in a book to compare with, since there are no results in image search engines for either Platismatia stenophylla or a synonym, Cetraria stenophylla. Nope, I was wrong – Evernia prunastri is a better match. This taxon's native range of occurring in coastal forests of temperate western North America matches, as does its property of growing on trees – so perhaps I'm right. To help be certain, I'd have to break out the chemistry kit. As I've noted before, lichen identification is often aided by observing reactions to chemical reagents (if you ever see a person in a forest with a satchel of small bottles covered by eyedroppers, you will have encountered a bona fide lichenologist).
For Platismatia stenophylla Evernia prunastri, confirming that it is either KC+ (yellowish) or KC- would help verify my tentative identification. This test would involve first wetting the thallus (body) of the lichen with a ten percent potassium hydroxide (KOH) solution, or the K test. The C test would be a dose of bleach, that is, a solution of sodium hypochlorite. If there is no apparent reaction to the bleach on the KOH-soaked lichen, another bit of evidence would be in agreement with the identification. If the test was positive, however, the thallus would change colour. For this lichen, a change to a yellowish colour would help confirm. If it changed a different colour, I'd be back to scratching my head over other possibilities.
The Oregon Coalition of Interdisciplinary Databases has a good entry on Evernia prunastri, and image search comparisons also suggest a match.
The hybrid witchhazel poses a different sort of mystery. Occasionally in the past few years, some staff time has been invested in attempting to verify that a cultivar 'Fireglow' exists. So far, we've come up short. Staff from the garden have searched online, reviewed the horticultural literature and even contacted the International Cultivar Registration Authority for Hamamelis, all to no avail. Its existence as a cultivar could be due to something as simple as a clerical error in its thirty year history. Or, perhaps it is a locally-developed selection, named and sold only to a select few three decades ago (it was purchased from a now-closed local nursery). Too, it could be a misidentification and actually an entirely different cultivar. We haven't yet figured it out.
Photography resource link: Tripod Therapy, an article by Rod Barbee for Nature Photographers Online. Good advice regarding one of photography's most important tools.
Posted by Daniel Mosquin at 12:00 AM| Comments (11)
November 9, 2005
Xanthoria elegans
Elegant sunburst lichen seems to be distributed throughout every province and territory in Canada (the national lichen?), most of the western United States, and parts of the northeastern US and southern Appalachians. According to “Lichens of North America” (ISBN: 0300082495) by Brodo, Sharnoff and Sharnoff, it prefers open rocks rich in nutrients. A bit of perspective is required – an open rock rich in nutrients to a lichen is one that is often “fertilized” with the excreta of birds or mammals. The authors also write that Inuit hunters could use concentrated groupings of the lichen to locate the burrows of hoary marmots. You can read more about this lichen from the authors here, on the site that ties in with the book.
Botany resource link: Two articles today, both on the same subject and written by Dr. David Hershey on ActionBioscience.org – Avoid Misconceptions When Teaching about Plants and More Misconceptions to Avoid When Teaching about Plants. I read both with an eye to seeing if I'd propagated any misconceptions, and I think I've avoided any of these pitfalls so far.
Posted by Daniel Mosquin at 12:00 AM| Comments (14)
October 28, 2005
Racomitrium canescens and Cladonia spp.
The boulder beneath this miniature jungle was part of the same rock slide as the rock in the BPotD entry on lichen diversity, yet it supports different organisms. Unlike the dome-shaped rock less than 10m away that was covered by the crustose lichens, this boulder has crevasses and depressions which accumulate water, air-borne dust and organic material at a comparatively rapid rate. After forty years, this boulder is not only blanketed by these non-vascular organisms (roadside rock moss, pixie cup lichen and club cladonia), but some vascular plants have started to colonize it as well: parsley fern, grasses and saxifrages – a small-scale example of ecological succession.
Botany resource link: Native American Ethnobotany database from the University of Michigan - Dearborn. “A Database of Foods, Drugs, Dyes and Fibers of Native American Peoples, Derived from Plants.”
Posted by Daniel Mosquin at 12:00 AM| Comments (1)
October 25, 2005
Lichen Diversity
The boulder forming the substrate for these lichens was part of the Hope Slide forty years ago. Unless this rock was previously exposed as part of mountainside (which I doubt), forty years of lichen colonization and growth have led to this mosaic containing six species or more.
As pioneers, these crustose lichens play an important role in the establishment of succeeding (i.e., sequentially following) organisms such as mosses or vascular plants. The bulky tissue of the lichen (particularly the thallus, or body) slowly traps air-borne dust and silt, while the fungal hyphae of the lichen penetrates and helps etch a thin layer of the rock's surface. The fine particles of soil in combination with dead or decaying lichen tissue form a medium where moss spores or vascular plant seeds can establish and grow. Over a long period of time (assuming no mechanical disturbances), a layer of mosses and herbaceous plants will replace these lichens. Although the period of time may be measured in decades or centuries, it is essentially instant in the scale of geologic time.
If you'd like to see this photograph in more detail, I've uploaded it here: Lichen Diversity (1.3 MB).
Botany resource link: 100 Plant Facts for Campaigning Conservationists from the excellent Plant Talk magazine.
Posted by Daniel Mosquin at 12:00 AM| Comments (1)
October 9, 2005
Rhizocarpon geographicum
Yellow map or world map lichen is frequently used in lichenometry, a geobotanical technique employed to estimate the age of exposure of a rock surface. Since Rhizocarpon geographicum quickly colonizes newly-exposed rock surfaces and has a known rate of growth, geologists can, for example, examine glacially-deposited rocks and determine the rate of glacial retreat. For an excellent introduction to lichenometry, read Lichens, Lichenometry and Global Warming (PDF), a short and well-illustrated paper by Richard Aston in the September 2004 issue of “Microbiologist”.
Photography resource link: Photographer and writer Freeman Patterson. To see a sampling of his photographs, click on Prints. Use the small vertical grey bars to access different albums of his images.
Posted by Daniel Mosquin at 3:54 AM| Comments (3)
October 5, 2005
Lobaria pulmonaria
If you like to keep track of milestones, today is Botany Photo of the Day's six month anniversary. I suppose I should celebrate the milestone with a showy flower, or at least some colour other than green (the dominant colour in many recent photos), but I'm going to sneak in one more “green thing” before sharing some autumn colours over the next few days.
Lobaria pulmonaria, or lungwort, is a lichen found widely around the world. I've not been able to track down a complete distribution for the species yet, but I've so far found references to: western North America, eastern North America, central and northern Europe, boreal forests of temperate Asia, and an interesting outlier, India (with its subtropical / tropical climates).
This species is highly sensitive to sulfur dioxide. An increase in atmospheric pollution is partly responsible for a noticeable decline in the species over the past century (habitat loss is another), so much so that it is often listed as endangered or rare in countries of Europe.
Although this lichen commonly grows on trees, mossy rocks and wood in shady mature forests, I found it on the side of a path, apparently fallen from a tree. Sad perhaps (for the lichen), but essential as part of a nutrient input process in old-growth forests. Lobaria pulmonaria hosts a nitrogen-fixing cyanobacteria, which pulls in atmospheric nitrogen into the body of the lichen. Eventually, when the lichen falls to the forest floor and decays, the nitrogen is then added to the soil, providing a necessary nutrient for a suite of plants. Marie Antoine, in “An Ecophysiological Approach to Quantifying Nitrogen Fixation by Lobaria oregana” (The Bryologist Vol. 107(1)) found that the related species, Lobaria oregana, could add over 15kg of nitrogen / hectare to the soil every year in some of the studied sites!
Photography resource link: May the Art Be With You, an article by Donna Bollenbach for Nature Photographers Online Magazine, reminds that the artistic quality of the photograph should be considered before pressing the shutter button.
Posted by Daniel Mosquin at 1:28 AM| Comments (3)
May 18, 2005
Letharia vulpina
There are two species in the genus Letharia (the wolf lichens), and both can be found in western North America. This particular lichen was found growing at the trunk base of a Pinus ponderosa near Merritt, British Columbia.
Wolf lichens are so named because of their common use as poisons for wolves and foxes in Europe centuries ago. The lichen, with its toxic vulpinic acid, was mixed with ground glass and meat, apparently a deadly combination.
The lichen was also used as a source for making a yellow-coloured dye, which is not difficult to imagine.
Posted by Daniel Mosquin at 12:00 AM| Comments (11)
May 4, 2005
Peltigera membranacea
This is “membranous dog-lichen” interwoven with a species of beaked moss (likely Kindbergia oregana, but I could be convinced it is Kindbergia praelonga). The “pelts”, as members of the genus Peltigera are commonly known, are perhaps my favourite lichens. How can one find fault with their texture, colour and form? And how can one not be intrigued by the lichens anyway, “organisms” that are actually a composite of a fungus and either green algae or blue-green algae (or, on occasion, all three!)?
If you look closely, you'll see a few orange-red structures along the edge of the thallus (the body of the lichen). These are the apothecia; these fruiting bodies from the fungal portion of the lichen will eventually release spores. However, spore release is thought to be a poor way for lichens to reproduce - when the spore reaches its new environment, the fungal component of the lichen begins to grow, but it must somehow find its related alga. It is thought that lichens better propagate themselves through breakage and distribution of a part of the thallus, which distributes all parts of the composite organism to the new environment.
Ethnobotanical note: In Lichens of North America (a must-have book for any lichenophiles), the authors state that the membranous dog-lichen was used by the Kwakiutl tribe of northwestern BC as a love charm. The authors go on to wonder, “it is not clear how (or if) it worked”. I've been trying out a few different methods with it for this purpose, but I haven't been successful yet. I'll keep you posted.
Posted by Daniel Mosquin at 12:00 AM| Comments (1)
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Botany Photo of the Day and all associated images are licensed under a Creative Commons License.
Botany Photo of the Day is a project of the UBC Botanical Garden and Centre for Plant Research, located in Vancouver, British Columbia Canada. UBC BGCPR is a department of the Faculty of Land and Food Systems within The University of British Columbia.