Mosses
May 15, 2008
Polytrichum juniperinum
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.
Posted by Daniel Mosquin at 3:58 PM| Comments (5)
April 28, 2008
Rhizomnium glabrescens
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.
Posted by Daniel Mosquin at 4:02 PM| Comments (3)
February 27, 2008
Tortula muralis
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).
Posted by Daniel Mosquin at 12:00 AM| Comments (14)
October 26, 2007
Unidentified Moss
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.
Posted by Daniel Mosquin at 7:14 AM| Comments (10)
October 6, 2007
Skagit Valley Provincial Park
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.
Posted by Daniel Mosquin at 7:20 AM| Comments (9)
May 1, 2007
Dawsonia longifolia
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.
Posted by Daniel Mosquin at 6:04 AM| Comments (2)
February 22, 2007
Unidentified Moss
Conduction of water in bryophytes (mosses, liverworts and hornworts) is broadly classified in three ways: ectohydric, mixohydric and endohydric.
Ectohydric bryophytes lack any form of specialized cells for internal conduction. Instead, water is conducted externally, typically through capillary action. Reliance upon external conduction, I'm certain, is correlated with height of these organisms – they tend to be the shortest of the bryophytes.
Today's photograph of an unidentified bryid moss is an example of a mixohydric bryophyte. While some water is conducted externally, these organisms have a measure of internal cell specialization, such as hydroids or stereids, that give them the ability to move water and nutrients within its tissues. It is not bona fide conducting tissue, i.e., it does not form an interconnected system throughout the entire body of the plant (including leaves or entire length of the stem), but it does represent a rudimentary way to transport water internally and decrease reliance on external moisture for growth and reproduction.
The third grouping, endohydric bryophytes, is represented by this BPotD on Polytrichum juniperinum. In these plants, an internal conducting system exists that is analogous to the conducting system of vascular plants. By no coincidence (as is mentioned in the Polytrichum link), this grouping contains the tallest of bryophytes reaching over a half metre in height.
In all three broad groupings, it is important to note that water uptake tends to be from atmospheric moisture (suggested in today's photo) absorbed via the leaf or stem cells as opposed to uptake in moisture from the substrate (compare with vascular plants, which often uptake moisture via roots in soil). For both ectohydric and mixohydric bryophytes in particular, this means that water is absorbed near the top of organism and passed downward to subtending tissues, the inverse of the way one typically thinks about water uptake in plants.
Photography resource link: For inspiration, the photomicrography of Hans Van Rafelghem.
Posted by Daniel Mosquin at 6:02 AM| Comments (14)
January 26, 2007
Rhytidiadelphus triquetrus
If I had to make a list of my favourite top ten common names for plants, this one would surely be among them. I'll quote from Schofield's “Some Common Mosses of British Columbia”: Commonly called the rough neck moss or shaggy moss because of the untidy leaves at the shoot tips. A whimsical name, electrified cat tail moss, has gained some popularity in British Columbia (emphasis added). The USDA Plants Database uses rough goose neck moss, as yet another alternative. I'll stick with electrified cat tail moss. Had E. E. Cummings Walt Whitman (see comments) been a bryologist, I'm sure he would have written, “I sing the moss electric.” for this particular species.
Rhytidiadelphus triquetrus is circumpolar for the northern hemisphere in its distribution, extending south into lower latitudes along mountain ranges (e.g., California and Arkansas). A broad range typically means a plant can grow in a variety of conditions, and it is no exception. Substrates for this moss species include well-drained sites in coniferous forests, on boulders and logs and, less frequently, tree trunks (source is again Schofield's book), though Mosses and Liverworts in Wales also mentions dunes and “certain types of broad-leaf woodland”.
Photography resource link: From Guy Tal's “The Essential Landscape” series: In the Name of All That is Good – On the Roles of the Artist, the Activist, and the Critic via Nature Photographers Online. Guy questions whether it is possible to be both artist and activist.
Posted by Daniel Mosquin at 12:00 AM| Comments (8)
April 3, 2006
Sphagnum squarrosum
I'm on vacation, so only a short written accompaniment today. – Daniel
Spread-leaved peat moss or rough peat moss is native to wet, acidic areas of Asia, Europe, North America, northern Africa, New Zealand and Greenland according to the Moss Flora of China entry on Sphagnum squarrosum.
Although it is very easy to recognize the distinctive peat moss from other mosses, identification of individual Sphagnum species often requires the use of a microscope. Complicating matters is that a sample of peat mosses may contain more than one species growing within the same clump (a personal observation).
Posted by Daniel Mosquin at 12:00 AM| Comments (5)
March 26, 2006
Orthotrichum lyellii
I'm on vacation, so only a short written accompaniment today. – Daniel
Orthrotrichum lyellii is a corticolous moss – its preferred substrate is the bark of trees and shrubs. It isn't particularly fussy about what species it grows on, as it can be found on both coniferous and deciduous woody plants. Despite this generalist characteristic, the moss is only distributed in coastal western North America and parts of Europe.
Posted by Daniel Mosquin at 12:00 AM| Comments (1)
March 5, 2006
Pohlia nutans
Copperwire moss has a truly global distribution. I wasn't able to locate a distribution map for the species, but I did find references to it occurring in North America, the Phllippines, China, Turkey, northern Europe, Chile, Australia and Antarctica.
The epithet nutans means “drooping” or “nodding”, in this case referring to the maturing capsules.
Botany resource link: The Wollemi Pine – thought to have gone extinct over two million years ago, nearly one hundred living trees of the Wollemi pine were discovered in 1994; they have been a botanical sensation since.
Posted by Daniel Mosquin at 1:56 AM| Comments (3)
December 24, 2005
Buckiella undulata
The unintentional (until today) three-part series on elongated, serpentine natural forms concludes with the aptly-named “snake moss”. Snake moss (or tongue moss) grows primarily in coniferous forests of north temperate maritime regions, but is also found in China and New Guinea (!). The genus Buckiella was separated from Plagiothecium in a 2001 paper (Ireland, RR. 2001. Buckiella, a new genus in the Hypnaceae (Musci). Novon. 11:55-62), so if you search for this moss in field guides, it is likely listed under the name Plagiothecium undulatum.
Unlike many of the name changes discussed via BPotD, the split was based off a morphological dissimilarity instead of molecular evidence. For more on the reasoning, see the Bryophyte Flora of North America's entry on Buckiella undulata. You might also appreciate the line drawings that accompany the entry.
Photography / art resource link: Photography at the Tipping Point, an article from Canadian Art Magazine on the meaning of digital photography: “But what will photography be when it is no longer connected to the world out there as a material trace? Will it be photography?”.
Posted by Daniel Mosquin at 3:58 AM| Comments (0)
November 30, 2005
Polytrichum juniperinum
Juniper haircap moss is a botanical citizen of the world, occurring on every single major continent (including Antarctica!). Haircap mosses are so named because of the fibrous covering which protects the developing sporophyte from water loss. In botanical terms, the haircap would be known as a hairy calyptra, and is present within most genera of the group. When the sporangium matures and the spores are ready to be released, the calyptra falls off so that the spores can be dispersed unimpeded. To see what the mature sporangium looks like underneath the hairy calyptra, scroll down to the last four photographs on this page for the closely related Polytrichum commune.
Some of the other images on that page show cross-sections of the Polytrichum stem. Unlike most other mosses, members of the subclass Polytrichidae have tissue specialized for the transport of water and nutrients (the hydromes and leptomes), analogous to what can be found in ferns, gymnosperms and flowering plants. The presence of conducting tissue allows this group of mosses to be relatively large compared to other mosses, and indeed, the tallest known moss, Dawsonia superba of New Zealand, can grow to a height of 50cm. I haven't been able to find an online image that illustrates the size of Dawsonia superba, but you can get an idea by checking out Dawsonia grandifolia (image number 7) on this page with plants from New Guinea, though I only estimate the height of those mosses to be 20cm or so.
Botany / photography resource link: Epimediums via Darrell Probst, Epimedium guru. If you're interested in reading more about Darrell, check out this interview from Fine Gardening magazine.
Posted by Daniel Mosquin at 12:00 AM| Comments (4)
November 10, 2005
Mycena sp. and Hylocomium splendens
I think the mushroom is one of the over two hundred species of the genus Mycena, but after reviewing a number of books, I still can't be absolutely certain. Mushroom identification is perilous without spore prints and other information from the field (does it smell? does it ooze if broken?). If I'm wrong, please add a comment and I'll update.
The moss, however, I'm certain of the identification. Hylocomium splendens, or stair-step moss, really deserves a photograph of its own to reveal its illustrative common name – you only get a hint of its arching main shoots in these photographs. I didn't photograph the moss on its own while at Bridal Veil Falls Provincial Park, but Hylocomium splendens can also be found in UBC Botanical Garden, so watch it for in an upcoming BPotD.
The reason for today's two similar photographs is to illustrate the difference in depth of field by changing the F value via the camera's aperture priority mode (read more in this tutorial). The first photograph was taken at F11 while the other was snapped at F4.5. For my purposes, I consider the first image more technical as it supplies more information about the Mycena's environment, while the second isolates the subject, which I find more aesthetically-pleasing. Finding a balance between providing enough technical detail and making a visually-appealing photograph is one of the challenges of scientific photography.
Meeting that challenge is where having a digital camera shines, because of the opportunity to take multiple images at essentially no additional cost. In almost all of the images shown on BPotD, my method has been to bracket the photographs using changes in F-value, i.e., taking a number of images with different depths of field. I then choose one or two out of a batch of up to a dozen to keep (sometimes at opposite ends of the depth of field spectrum, like these two). Of course, this means making decisions, or else the hard drive quickly fills up. Still, it's a pretty good recipe for success if you're disciplined and ruthless. As an aside, I was inspired to write on this topic because of a posting on one of my favourite non-science weblogs, Creating Passionate Users – read Kathy Sierra's article on “If you could change only one thing...”.
Photography resource link: Science and Photography Through the Microscope, by award-winning photomicrographer Dr. Dennis Kunkel. Plenty of botanical images (and others) under the Search the Image Library link.
Posted by Daniel Mosquin at 12:00 AM| Comments (16)
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)
May 19, 2005
Takakia lepidozioides
(Quentin Cronk, Director of the UBC Botanical Garden and Centre for Plant Research has kindly offered to guestblog today -- Daniel)
This photograph was taken at Jervis Inlet, British Columbia, on a very enjoyable Botany graduate field trip with UBC bryologists Shona Ellis and Wilf Schofield (co-author of the Takakiaceae for the Bryophyte Flora of North America project), organized by graduate students Nyssa Temmel and Chris Sears. The photograph was taken standing on a boulder in a wet gulley in the persistent drizzle of a typical March day, having arrived in a hired motor boat at the head of Jervis Inlet (the site is not accessible by road, nor would it be possible to hike in). The boat was gently beached so that we could jump off into the shallows.
The moss Takakia is interesting for many reasons, not least because when discovered it was thought to be a liverwort! Hooker collected specimens of another species in the Himalayas in the mid-19th century, which Mitten described as a liverwort, Lepidozia ceratophylla. Without seeing the sporophytes (capsule bearing structures full of spores), which are rare, this was quite a reasonable identification. Sporophytes were later discovered in Alaska. These were clearly moss-like and recent DNA data have confirmed its status as a moss. The British Columbian species, Takakia lepidozioides, also occurs in both Asia and Alaska, while the other species, T. ceratophylla, is confined to Asia and Alaska.
The reason sporophytes are so rare is that there are separate male and female plants which reproduce asexually, so large patches of a single sex develop, unable to produce the sporophytes (which result from fusion of male and female gametes). All the plants in British Columbia appear to be female, so sporophytes are not expected anytime soon. The male plants may have become extinct during one of B.C.'s ice ages. The presence of an ice sheet would confine Takakia to small refuge areas. It is possible that a male spore will blow in from Asia one day and start the sexual process once more in B.C. However, this may not happen for millions of years.
The plants are very small and the leaf segments are typically only one or two cells wide. This photograph covers roughly the area of a postage stamp.
Several interesting features can be seen. It is a very wet site on a dripping rocky cliff near a waterfall in the heart of B.C.'s coastal rainforest, and the wet conditions encourage a growth of "bluegreen algae" (cyanobacteria) that produce the prominent slime. Clearly visible in this photograph are the long green leafless "stolon shoots" which allow the plant to colonise bare areas. The leaves are bifid (deeply split into two segments) and this is obvious in a few places. Also visible are a few white "rhizomatous shoots" which give rise to the normal leafy shoots. Oil bodies are present in some of the cells and this results in the plant having a cinnamon smell when dry.
Posted by Daniel Mosquin at 12:00 AM| Comments (0)
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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.