#thallose liverwort

[botanybyyen]

This weeks microscopy features Marchantia polymorpha (Marchantiaceae), a species of thallose liverwort! Called the ‘common liverwort’ this species is probably the most well known of thallose liverworts. It is found on every continent except Antarctica and is used as a model organism. It can often be a horticultural weed and is very commonly seen in potted plants at nurseries. Which is exactly where I picked up this specimen. I had bought tubestock of an Acacia specifically for the reproductive Marchantia it contained, not actually for the Acacia.

There’s a few features I wanted to share (and part of why I got soooo excited when I saw this plant).

First off, air pores! These are almost the equivalent of stomata in higher plants. Their function is in gas exchange and they are those pin-prick like features surrounded by a whitish circle.

Next, a gemmae cup! For Marchantia these cups are circular (as opposed to crescent-shaped like in Lunalaria). Gemmae cups house asexually-produced gemmae that disperse via water. You can just make out some of them in the centre here.

Now we have my two favourite photos from the whole shoot. These are archegoniophores, which contain the female sex organs. They're stalked and tall and just stunning. Let's look at their underside.

These are mature sporophytes on the underside of the archegoniophore. They're orange/yellow and actually look like mini flowers or something. You can just make out the feathery fine threads of spores on the first image there. They're gonna go off and make the next generation of Marchantia.

Lastly we have an antheridiophore. These contain the male sex organs. There was only one on the specimen I got but thankfully it worked out, it wasn't too old to get goof photos of.

Anyway, hope you've enjoyed this little Marchantia appreciation post. I loooooove liverworts and need to make time to photograph more of them.

[fieldguidetothenarrativeforest]

[1: Clayton, VIC, Australia | 2: Baw Baw, VIC, Australia]

Scrolling iNaturalist to try to ID my moss samples, I discovered the light green sprawling one is actually a leafy liverwort.

Nonvascular plants remind me of miniaturised rainforests in the same way circuitboards remind me of cities bustling with resistor-cars around capacitor factories and microchip houses.

[vandaliatraveler]

Liverworts (Marchantiophyta) are small, non-vascular plants with a fascinating lifecycle typical of the bryophytes, which include mosses and hornworts. Due to their small size and growth habit, these primitive beauties are often overlooked, but they’re actually quite common. I often find them growing in the “splash” zone of shady seeps and brooks, typically clinging to rock surfaces. There are two types of liverworts: thallose liverworts, whose scaly, flat surfaces branch out in a “Y” pattern; and leafy liverworts, which have overlapping, leaf-like scales arranged in at least two rows. The photo above is of snakeskin liverwort (Conocephalum salebrosum), a thallose liverwort I found growing in a seep along the Mon River Trail. As you might surmise, liverworts make dramatic show plants in terrariums, especially if you can get them to sprawl over a rock surface.

[botanybyyen]

This weeks microscopy features Lunularia cruciata (Lunulariaceae). Lunularia is a monotypic genus, meaning L. cruciata is its only species. This thallose liverwort is pretty unmistakable due to its crescent-shaped gemmae cups, which look like little crescent moons (hence the name!). They definitely don't make the liverworts look like they have little faces.

It's widespread around the world but is introduced in Australia. Still, it's one of the most common liverworts you'll see in urban areas.

It reproduces almost entirely asexually through its gemmae, which are water-distributed. Sexual reproduction is quite rare in this species, so no photos of sporophytes this time around!

I do, however, have this series. First photo shows gemmae that have spashed off the thallose and onto dirt, where they'll slowly grow (second photo) into mini thallose liverworts. You can also see green tendrils of algae in the first photo, which are really common on moist soil.

And as a bonus, here's a springtail that sat very nicely for some photos.

[botanybyyen]

This weeks microscopy features Fossombronia (Fossombroniaceae)!

Despite looking like miniature heads of lettuce, these plant are thallose liverworts. There are ~25 species found in Victoria but most look alike except for their spores. Thus, they can be very hard to ID accurately without looking at spores under the microsope (hence not providing a species here, though I'd wager it's Fossombronia pusilla).

This specimen here is reproductive, and you can see the black spore-containing capsules and clear seta that make up the sporophyte.

This capsule had opened up and you can see that the spores are brown coloured.

[stefano-bonalume]

Marchantia polymorpha - Thallose Liverwort