Another thank you to Orthotrichum@Flickr (aka Robert Klips) for sharing a photograph of a small wonder from Ohio (original posting via the Botany Photo of the Day Flickr Pool).

I'll also quote Robert's accompanying text from Flickr, for stellate orthotrichum moss: "Orthotrichum stellatum is a cushion moss that grows in small tufts on tree trunks or limbs in moderately moist woodlands in eastern North America and parts of Europe. It is distinguished from several similar Orthotrichum species by techical features of the sporophyte capsule: immersed stomates bordered by horizontal, not upwardly-jutting cells, a deeply wrinkled shape when dry, and a peristome of 8 teeth tending not to become split into 16 teeth. This specimen was photographed March 17, 2012."

One of those similar species that Robert mentions is Orthotrichum ohioense (via Ohio University).

Thank you once again to Huenchecal.@Flickr, (associated with Chilebosque, a site about the native flora of Chile) for sharing an image from Chile (original via the Botany Photo of the Day Flickr Pool). It's great to have identified moss species available for BPotD from time to time.

Leptostomum splachnoideum is native to southern Chile and Argentina (map of Chilean collection sites). It is primarily, if not exclusively, epiphytic. Collections to date have occurred between 0 and 1000m. The name of the genus is derived from lepto- meaning "fine" or "slender" and stoma- meaning "mouth". The narrowing of the spore capsule to a small opening, as shown in today's photograph, is presumably what is meant by the name of the genus. The epithet splachnoideum is a reference to Splachnum, a genus of mosses commonly known as the dung-mosses. When an epithet like this is used (ending in -oideum or -oides, it means there is a readily-apparent morphological similarity between the species and another entity or group (e.g., Populus tremuloides is similar in appearance to Populus tremulus).

Today's species was first collected for science during the 1825-1828 voyage of the HMS Blossom, captained by Frederick William Beechey. It took over a decade before it was described and published in The Botany of Captain Beechey's Voyage.

For more on Leptostomum, see: Hyvönen, J. 1987. A synopsis of genus Leptostomum (Leptostomataceae, Musci). Annales Botanici Fennici 24: 63-72. (website of the author: Dr. Jaakko Hyvönen of the University of Helsinki).

Alexis wrote today's entry:

Robert Klips (Orthotrichum@Flickr) shares this photo via the Botany Photo of the Day Flickr Pool. He writes, "Plagiomnium ciliare (Mniaceae) is a common woodland cushion moss. Like many mosses, male Plagiomnium plants produce their antheridia in terminal clusters surrounded by a rosette of leaves that forms a splash cup to disperse sperm during rainy weather. This specimen was photographed May 7, 2011 on a large boulder in a moist shady forest in Hocking County, Ohio, USA." Thank you, Robert!

Plagiomnium ciliare is a moss endemic to Canada and the USA, growing on moderately dry substrates of soil, rocks, tree bases, rotten logs and stumps (Ireland's Moss Flora of the Maritime Provinces (1982)). The plants are green to yellow-green in appearance, creating loose or dense tufts 3-9cm high (Conard and Redfearn's How to Know the Mosses and Liverworts from 1979). This species is dioicous, meaning that a given gametophyte will yield either sperm or eggs, but not both. Additionally, the sporophytes are solitary, a single stalk (seta) occurring on any one gametophyte. The leaves are elliptic and have margins that are toothed almost to the base.

The name of the genus comes from the Greek word plagios, meaning "oblique, transverse, or slanting", and mnion, simply meaning "moss".

Alexis wrote today's entry:

Robert Klips (Orthotrichum@Flickr) snapped this photo of an apple moss in Gallia County, Ohio, USA. Thanks for sharing, Robert!

Species of Bartramia, including the pictured Bartramia pomiformis, are called apple mosses because of the round shape of their sporangia (spore-containing capsules). One of about one hundred species in the genus, Bartramia pomiformis has a circumboreal distribution, extending from arctic latitudes to as far south as North Africa. This species forms loose tufts and turfs on moist rock outcrops and cliff shelves, from subalpine elevations down to sea level (see Schofield's Some Common Mosses of British Columbia and Vitt et al's Mosses, Lichens & Ferns of Northwest North America).

Bartramia pomiformis is distinguished in part by its long, slender and flexuous leaves, which are light green to bluish-green in colour. When dry, however, the leaves are twisted and contorted (see Ireland's Moss Flora of the Maritime Provinces).

Bartramia pomiformis can be confused with Bartramia ithphylla, though the latter is only found in alpine and subalpine areas and its leaves remain straight when dry (from Schofield's Some Common Mosses of British Columbia 1992). Also similar is Bartramia stricta (PDF), which lacks sheathing (leaves clasping and surrounding the stem base) and whose wet leaves are typically more erect than those of Bartramia pomiformis.

A lot of thank-yous are in order for today's entry. First of all, thank you to Wouter Bleeker of the Geological Survey of Canada for sending me today's images via email. Wouter is responsible for the first two photographs, and his friend Mike Stubley is the photographer of the third. Also, thank-yous to local bryologists Terry McIntosh (speaker at next week's Cedar Series Lecture) and Steve Joya for their attempts to identify these mosses without having samples in hand (identifying mosses from photographs is nearly impossible without a lot of close-up images). I'll add one more thank-you in the last paragraph of this entry as well.

Since the identifications are tentative, today's entry will instead be about the phenomenon shown in the images, on which Wouter wrote:

"For my field work I am up in the (sub)Arctic quite a bit, and here I attach some pictures of an interesting plant phenomenon: mobile moss or what we jokingly call "galloping moss". These mosses are slowly creeping downhill, probably by daily frost-thaw cycles in spring and fall, and they seem perfectly happy with the movement. I have seen it in different moss species, including Sphagnum (not shown). Sometimes they stall out at a little crack or ridge, like in the first photo, only to start moving again after a while. If the hill side steepens, their leading edges may be overrun by the rest and things get a little messy, but otherwise all is fine. Some other species sometimes seem to catch a ride, as a small Saxifraga species in the second picture (upper right)."

"The most interesting aspect, perhaps, is that they leave this time-dependent trail from where they came, with the surface just vacated, bleached in the sun for 1-2 years or so, nice and clean; further back other algae and lichens slowly start growing back again. I don't know the duration to full recolonization of the rock surface but this could be figured out and calibrated. It is probably on the order of 10-20 years. Just by coincidence, in the first two pictures the moss carpets are growing on stromatolitic limestone, formed by 1.9 billion year old cyanobacterial mats on a shallow, warmish, seafloor. These rocks are now exposed on the East Arm of Great Slave Lake, NWT. The third photo is from further north in the barren lands."

Assuming the species identifications are correct, a few links: Grimmia ovalis (oval dry rock moss) and Niphotrichum ericoides in the Flora of North America, Niphotrichum ericoides (includes close-up photo) via the Natural History of Southeast Alaska, and Grimmia ovalis (with photographs) from the USDA PLANTS database.

On a different topic (and a different thank-you): my gratitude to Edmund Seow, Computer Systems Manager in the Faculty of Land and Food Systems here at UBC, for helping return Botany Photo of the Day (and the rest of the BG web site) back to normal. I think all issues are now resolved, and even though things will be changing again in April with the redesign of the entire UBC BG site, a problem-free web site for the next two months will be a huge relief.

While participating in last month's Burnaby Lake BioBlitz on behalf of the garden, local bryologist Steve Joya introduced me to this moss species and suggested it would be a good Botany Photo of the Day.

When the words "invasive alien plant species" pop up, people tend to think of large plants that affect the landscape on a human scale: kudzu or Japanese knotweed or Gunnera tinctoria. Few people will initially imagine an invasive moss, but Campylopus introflexus fits the profile: it is a rapidly-dispersing foreign organism that displaces native organisms in the ecosystem. Native to the southern hemisphere (southern South America, southern Africa, southern Australia, and various oceanic islands, Campylopus introflexus has made the distant leap into Europe and North America -- and is rapidly spreading.

In North America, the first record of the species (sometimes commonly referred to as heath star-moss) is from the gravel roof of a building at Humboldt University in Arcata, California. It has since spread throughout coastal western North America -- in the span of 35 years. Several examples of its impact on a native ecosystem are available from the European Network of Invasive Alien Species. From the Campylopus introflexus factsheet (PDF), which details its spread in Europe after a 1941 initial observation in England:

"Carpets of Campylopus introflexus markedly reduce the regeneration of Calluna vulgaris...in the field in a Danish heathland. The reduction in the number of germinating Calluna vulgaris seeds may be caused by lack of light as well as desiccation in the dense moss carpet. In the Netherlands typical grasses and herbs as well as lichens and other mosses of the dune vegetation have been out-competed by the aggressive moss due to acidification of otherwise calcareous dunes...The decline of the Tawny Pipit (Anthus campestris) as breeding bird in The Netherlands was probably caused by the decrease of suitable breeding habitat, open short grasslands, due to the invasion of Campylopus introflexus, which formed dominant and dense stands. A further consequence of these closed moss carpets was a decline of arthropods as food source for these birds...In Iceland Campylopus introflexus invades high-temperature geothermal areas often with species rich moss flora. Some very rare species have already been affected..."

Please consult the factsheet for references to the observations, as well as images illustrating this moss species acting as an invader.

Art resource link: the American Society of Botanical Artists has a touring exhibition of major US public gardens called Losing Paradise? Endangered Plants Here and Around the World. Fortunately for those of us who don't have the opportunity to visit, we can enjoy excerpts from the exhibit online on the weblog Losing Paradise?. Link is via the Plant Conservation Alliance's native-plants mailing list.

A big thanks to Ruth for today's write-up. Ruth writes:

Thanks to Carolina Chanis for today's photograph.

Plagiomnium insigne is quite common on the University of British Columbia campus. Male plants are easily identified by their shoots and almost flower-like appearance. The dark green leaves are spirally arranged forming a cup-like shape at the tip. The club-shaped, dark-brown object in today's photograph is the antheridium or sperm-producing male reproductive structure. The structure to the left of the antheridium is a paraphysis, or sterile filament. A detailed image of the moss life cycle is available from Moss Plants and More.

Plagiomnium insigne, or giant moss / badge moss (visit link for photographs) can be easily identified when the sporophytes grow -- multiple sporophytes arise from one shoot, a relatively uncommon phenomenon. In British Columbia, it is the largest species of Plagiomnium, reaching 10 or more cm in height and more than twice as much in width. It creeps along the forest floor and on logs with long spindly shoots. As well as British Columbia, it is also found in southeastern Alaska and the western continental United States.

Bryophytes of Stanley Park has an excellent page on Plagiomnium insigne.

Ruth is again responsible for today's write-up:

I'm in a bryophytes course this term, and as I harvest knowledge from some of the most reputable human sources in the world I will be passing it on to you, the lucky reader. Bryophytes (mosses, hornworts and liverworts) are a group of plants that people rarely consider. In an urban environment, their presence is easily unnoticed unless they have claimed your front door or stone walkway as their own.

Without a microscope, this species looks like little green cushions or tufts on rock surfaces, preferably granite. They get a lot more interesting when put under a microscope or electron micrograph. This picture is one my lab partner Carolina Chanis took of Andreaea nivalis leaves under 10x magnification. Thanks Caro!

The Andreaeidae are commonly referred to as the granite mosses or lantern mosses. The lantern reference is due to the dried sporangium shape. Thanks to Shona Ellis for putting together this course website and supplying some awesome electron micrograph pictures of the sporangium of Andreaea nivalis as a complement to today's photograph of a leaf.

The gametophyte, or the haploid generation responsible for growth, is the green leafy part we typically associate with mosses, though in this species it can even be red-brown or black. When mature and ready to disperse spores, the sporangium dehisces along four or five lines to allow wind and water access. Also, the columella, or point in the centre of the sporangium, depresses to push out the sporangium wall and allow dehiscence. The genus Andreaea and Andreaeobryum are the only two genera within the subclass Andreaeideae. Members of the Andreaeidae tend to be found in mountainous and arctic regions of the world.

I hope you are intrigued as I have many more pictures, and I am becoming a wealth of information on these little cuties (midterm approaching).

It's been a tough year for the plant people at UBC. The most recent loss was the passing last week of Dr. Wilf Schofield, professor emeritus in the Department of Botany. An internationally-renowned bryologist (one who studies mosses and liverworts), Wilf had an immeasurable impact on the understanding of these diminutive plants (particularly in the Pacific Northwest of North America). Over a decade ago, Wilf was honoured with a special issue of the Botanical Electronic News, dedicated to him on the occasion of his 70th birthday: BEN 168. At the time, he had collected 107,990 bryophyte specimens -- over 4 per day for every day of his life. He continued to collect, I believe, until this past summer, and his collections form the majority of the UBC Herbarium's bryophyte collection.

I didn't know Wilf as well as I would have liked -- the garden and the botany department (and herbarium) are separated by a 15 minute walk, and there are too few occasions to visit -- but in all my interactions with him, including as a student, I recall only positive things: patience, curiousity, intellect. His death is a loss that will be shared by many.

This patch of stair-step moss / stepped feathermoss was also featured in this wider shot of the area.

Thank you to Connor Fitzpatrick for today's write-up. Just a small update re: Connor -- he completed his work-study position here at the garden a couple weeks ago, and moved on to a summer job in Alberta. Best of luck to him! Connor writes:

Today's Botany Photo of the Day features a moss commonly found in the Nitobe Memorial Garden. The photograph is courtesy Michelle Fitterer.

Polytrichum juniperinum can also be found in the E.H. Lohbrunner Alpine Garden of the UBC Botanical Garden. Previously, Daniel had mentioned that members of the Polytrichidae possess a well differentiated stem anatomy capable of transporting water and nutrients. Another interesting feature of this group is the presence of lamellae.

Lamellae are unistratose (one cell layer thick) flaps of tissue found on the upper leaf surface of many polytrichid mosses. The UBC BIOL 321 website proves to be (yet again) a fantastic resource when it comes to examining moss morphology. Scroll down the page to find a cross-section of a leaf. The lamellae are made up of chlorophyllose cells arranged in flaps to increase the available area for photosynthesis. A cuticle can be found at the top of the lamellae preventing water from leaving and entering the leaf surface. This is adaptive, because too much water in the microenvironment of the leaf surface would hinder gas exchange required for photosynthesis and the loss of water would quickly lead to dessication.

The severely recurved leaf margins, visible in the leaf cross-section and in the photograph, also prevent water loss. This feature in addition to the lamellae and the stem's conduction ability allow members of the Polytrichidae to tolerate very exposed sites. This tolerance is reflected by Polytrichum juniperum's cosmopolitan distribution.

The mosses, as well as the other bryophytes (liverworts and hornworts), represent the first plant colonizers of land and are an understudied group of organisms. In fact, it is still being debated as to whether the bryophytes evolved from a single ancestor or are each of a separate lineage. As there is probably at least one bryophyte adapted to every kind of plant stressor, it's surprising that more work isn't being done to understand the evolution and adaptive strategies of this incredibly diverse group of organisms. In Phylogeny and diversification of bryophytes, Shaw and Renzaglia provide a bird's-eye view of bryophyte phylogeny.

Well, I've managed to wrest Connor away from his exams for a bit. He's the author of today's write-up. Along with diving into today's write-up, I also suggest you visit Berry-Go-Round #4 at Foothills Fancies weblog. Berry-Go-Round is a weblog carnival devoted to plants.

Connor writes:

Many thanks to Michelle Fitterer for today's photograph.

Rhizomnium glabrescens is a moss that can easily be found in the Nitobe Memorial Garden. It forms a dense, shiny turf under the coverage of the garden's tiny forest. In Some Common Mosses of Birtish Columbia, W.B. Schofield reports that Rhizomium glabrescens is limited to western North America from California to Alaska and as far west as Montana.

The most striking features of this moss can be seen from this photograph. The leaves are a pale green colour with a pronounced costa, a central midrib of specialized cells. The costa is made up of a central conducting strand and thick-walled cells called stereids. The central conducting strand functions as a water transport and the stereids provide support for the leaf.

The leaf margin is also well differentiated. Marginal cells are elongate, lack chloroplasts, and are found in multiple layers (multistratose), while the rest of the leaf blade contains chloroplasts and is only one cell layer thick (unistratose). The UBC Biology 321 website provides excellent images of Rhizomnium glabrescens.

The male plants of Rhizomnium glabrescens possess a rosette of leaves making up the perigonial head. The dark cluster in the centre are many antheridia with paraphyses, sterile filaments of cells. Inside the antheridia, mobile sperm with flagellae are produced. The perigonial head acts as a splash cup, increasing the sperm's dispersal distance when a raindrop falls on it.

Connor Fitzpatrick is responsible for today's write-up:

This bryophyte (liverworts, hornworts and mosses), belongs to the class Bryopsida. Also referred to as the joint-toothed mosses, the Bryopsida account for 95% of all moss species. The common name refers to the fact that the peristome teeth found on the sporangium of these mosses are made from fragments of whole cells. The peristome teeth of this moss are hidden underneath a calyptra and an operculum. The UBC Biology 321 course website does an excellent job explaining moss morphology.

This particular moss, Tortula muralis, has a wide distribution and can be found on all but one continent. This incredible range is due in part to an ability to tolerate desiccation (water loss). Eric in SF@Flickr noted that he found this moss growing on a brick wall. As Daniel mentioned in a previous BPotD posting, ectohydric mosses such as Tortula muralis rely on external water conduction. Mosses are in constant equilibrium with their habitat. Water is travelling in and out of cells depending on the available moisture in the environment, a condition known as poikilohydry. Several physical features help this moss retain water in low-moisture environments (such as brick walls), including leaf extensions (awns) which reflect light & increase the laminar boundary layer and very dense, short growth. Another bryid moss that can be found on similar substrates and shares these features with Tortula muralis is Grimmia pulvinata. The ability to resist desiccation at the cellular level is an active area of research. Oliver et al. (PDF), compares the mechanisms of desiccation tolerance in bryophytes to those of vascular plants with the hopes of coming to a better understanding of the evolution of this ability throughout land plants. One such mechanism (PDF) found in the moss Tortula ruralis (not a typo), is the conservation of polyribosomes during desiccation. Polyribosomes are needed for the translation of mRNA into proteins. Upon rehydration, these conserved polyribosomes allow the moss to resume protein synthesis.

An understanding of the processes employed by mosses and vascular plants to “cope with severe water deficits has economic and agricultural implications that directly relate to crop productivity in an ever challenging and changing environment” (via Oliver et al.). Thank you to Eric in SF for a very interesting photograph (original via BPotD Flickr group pool).

Apparently, identifying the species of moss residing on top of a rock in the middle of a river is quite difficult. I put in a call to one of the local moss experts explaining my photograph, naively thinking that there can't be that many species of mosses living on stream-rocks. It turns out that there can be that many. Similar to terrestrial species of moss, a good macro photograph with fruiting structures (or even better, a specimen in hand) is required to take a stab at identification.

This photograph was taken in-camera and processed a bit less than I normally do. The effect of the water is due to a specialized glass filter and long exposure.

I made my annual trek yesterday to view the autumn colours (particularly Acer circinatum) in Manning Provincial Park and the adjacent Skagit Valley Provincial Park. In my opinion, the colours were average or a bit better along the Highway 3 roadside, so not as spectacular as the previous two years. On the hiking trail I went on, though, the colours were non-existent to below par. Admittedly, the trails don't seem to be as good as the highway roadside for colour, but the trails have the distinct advantage of being away from wind-causing, noisy highway traffic.

After a brief bit of disappointment regarding the maples, I mentally switched gears and started to photograph other things, like this scene from the Skagit River trail. There are two or three spots along the first 6km (3.75 miles) of the trail where the floor of the forest is dominated by the moss shown here, Hylocomium splendens for stretches of 50m (160feet) or so. Invariably, these are areas shaded by coniferous trees and therefore with acidic soils, but that combination of factors is present elsewhere along the trail where the moss isn't found in such quantity. So why only in these brief stretches? I don't know. If forced to make a guess, I would suggest two possible reasons (or a combination thereof): marginally increased local humidity or that this is a successional stage in the re-establishment of plants after a rock and mud slump. The latter strikes me as a good possibility; the ground beneath the thick layer of moss was quite rocky and, after the heavy rains of last year, a new rock and mud slump occurred elsewhere along the trail — approximately 50m wide!

From the Bryophyte Flora of North America entry for Hylocomium splendens, we learn that stair-step moss or stepped feathermoss is “one of the most common and widespread mosses of the circumboreal forest and Arctic tundra, which covers huge areas of Alaska, Canada, northern Europe, and Siberia” and also present in northern Africa, Australia and New Zealand. To view more photographs of Hylocomium splendens, visit the Bryophytes of North America photo gallery or the Northern Ontario Plant Database (the latter has a description of the moss and more resource links.

Thank you to Eric in SF@Flickr for sharing another photograph from Borneo (original | BPotD Flickr Group Pool). This photo is one of over 150 photographs in Eric's Borneo: All Other Plants, Flowers and Bugs photo set. Always appreciated, Eric.

What's particularly special about this moss is its freestanding height (and what that signifies). Eric noted a height approaching 15cm (6in) and alluded to online references suggesting a maximum height approaching 1m (3ft). That latter figure is higher than I've previously read for any member of this tallest family of mosses (~ 2/3 of that figure), but certainly plausible in ideal circumstances.

At the level of cells and tissues, Dawsonia is one of the most structurally complex of mosses. Some cells differentiate into analogues of the water and nutrient-conducting cells of vascular plants, while others become the thick-walled cells necessary to support the free-standing height. This combination, only present in a rudimentary way in some mosses (and absent in many), provides Dawsonia with the ability to internally transport water and nutrients. In most other mosses, the absence of this quality limits their height to under 10cm (4in).

Paradoxically, despite its tallest freestanding moss reputation, Dawsonia produces some of the smallest spores among mosses. Up to 65 million spores measuring 5-8 µm in diameter can be generated by a single sporangium, like the one shown in the upper part of this photo.

More photographs of Dawsonia longifolia (and there aren't many online) can be found in the University of Singapore's Interactive Malesian Moss Database.