Moss, moss, moss...

[archaeopteryx]

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[archaeopteryx]

I found myself wondering just how many individual leaves are in this picture. A Fermi estimate came up with about two million. That's four pixels per leaf in the original, which sounds about right given the spiral arrangement and an LAI around 3.5.
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[archaeopteryx]

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[archaeopteryx]

The aptly named big shaggy-moss (Rhytidiadelphus triquetrus). These individuals are exceptionally tall forest floor mosses for their location---about 8 cm---but perhaps Dawsonia superba or Spiridens reinwardtii might turn up in this thread.
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[archaeopteryx]

While nicely surrounded by moss, the subject of the now deleted post just prior to this one was a mushroom. So the fungi thread was probably a better fit. Fungal karyogamy and alternation of generations in plants are broadly different but both do have haploid and diploid phases and, in the case of bryophytes (mosses, liverworts, and hornworts) and ferns, involve spores. Mushrooms are spore dispersing fungal fruiting bodies. The equivalent structure in a moss is a capsule, which generally looks something like these in species where they're prominent (more examples in posts #1, 7, 20, 22, 40, and 41).
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The old trick of finding your way in the wilderness using, the rule of, moss always grows on the north side of tree trunks, isn’t really a very good trick at all.

Like any plant, mosses grow where they can obtain adequate light and water for photosynthesis (and take up sufficient nutrients). For an epiphytic moss, the sunward side of a tree offers more light and therefore also more heat, which increases evaporation and need for moisture. In the right circumstances there's still enough light on the shadier side of a tree but not quite enough moisture on the sunnier side and a moss population occupying one side of a trunk but not the other results. As you might expect from this description, it's a fairly fragile circumstance and is easily and routinely overridden by variations in stemflow (downward flow of water from precipitation) along a trunk or branch based on its shape, angle, and what's above it.

This should be enough of a hint to work out another reason why moss distributions are unlikely to favor the north side of trunks in your hemisphere.

It may also be interesting to look up rhizoids.

 

[archaeopteryx]

Plagiomnium insigne
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[archaeopteryx]

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[biomed]

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[archaeopteryx]

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[archaeopteryx]

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[archaeopteryx]

Higher magnification view of a bare patch being colonized not far from the image above.
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[archaeopteryx]

About 3x magnification to show another spiral arrangement of leaves.
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[Joris]

Plagiomnium insigne

Amazing ! Are what we see individual cells ?

 

[archaeopteryx]

Amazing! Are what we see individual cells?

Thank you, they are individual cells. In the earlier 200% crop the larger squamous cells along the leaf margins---which P. insigne shares with a few other species---are also visible. I had one chance near the end of the last rainy season to try to acquire imagery at higher magnification but weather conditions proved unsuitable. I'm looking forward to trying again in the next rainy season, though the cells will be only about 20 pixels wide at the upper limit of what I can use noninvasively in the field. Some of Heribert's changes to Picolay since the rainy season should also improve the stacking results somewhat.

Capsule of a mainly aquatic moss grown during the dry season, presumably because lower streamflow exposes it to the air, facilitating spore dispersal once the calyptra dehisces. (Also around 3x.)
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[archaeopteryx]

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[archaeopteryx]

In my current area it's been a wetter than usual dry season. Still likely to be some weeks before dry changes over to wet but a recent episode of rain's prompted some of the more rapid mosses to rehydrate, resume photosynthesis, and presumably start repairing some of their dessication damage. In addition to the brown spots you can see a few broken and torn leaves.
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As I think @Bushboy picked up on a few months ago, the colour here is more of a yellow green than some of the purer or darker greens in some of the images up thread. This seems consistent with known chlorophyll a and b shifts at brighter microsites (Marschall 2004, Soriano 2019, Fernández-Marín 2019) but may be an artifact of inadequacies in my current lighting and white balance management. (Among other things, there are 440 and 480 nm confounds between LED emitters and chlorophyll absorption peaks see, for example, DIPC 2015, Nichia, and Sunwayfoto.) Photosynthetic response rates are also likely comparable the time needed to compose an image (Kubásek 2014).

 

[archaeopteryx]

Hyaline awns and dessicated leaves of a lithophytic moss colony. 268 stack at 2.9x.
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[OldRex]

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[Bushboy]

Hyaline awns and dessicated leaves of a lithophytic moss colony. 268 stack at 2.9x.
View attachment 776056

Impressive magnification! Impressive stacking!
Well done.

 

[archaeopteryx]

Epiphytic 279 stack, probably around 2.2x.
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