Wednesday 13 April 2016

Mosses Again - And Liverworts


Rhytidiadelphus squarrosus, Springy Turf-moss.  Hayes Common, 9 March 2016.
Rhytidiadelphus squarrosus, Springy Turf-moss.  Hayes Common, 9 March 2016.
Another couple of mosses, because they are pretty.

With its reddish stems and green leaves set at an angle, Rhytidiadelphus squarrosus is quite distinctive.  It grows among grass, and in sometimes it forms the main ground cover.

Rhytidiadelphus squarrosus, Springy Turf-moss.  Hayes Common, 9 March 2016.
Rhytidiadelphus squarrosus, Springy Turf-moss.  Hayes Common, 9 March 2016.
This patch is at the edge of a grassy clearing.  The moss threads its way among the grass all over one side of the clearing, and at the edge it takes over completely.  It is wet here, because it has just been raining, but it can also grow in much drier grassland.

Bryum argenteum, Silver-moss.  Ridgeway, Hayes.  9 March 2016.
Bryum argenteum, Silver-moss.  Ridgeway, Hayes.  9 March 2016.
This moss, Bryum argenteum, seems to prefer the drier places.  It forms silvery patches on walls.  It is pretty and is also easily recognisable.

Closely related to mosses are liverworts.  Some are leafy, like mosses, but others form a green layer over wet ground.

Marchantia polymorpha subsp. ruderalis, Common Liverwort.   Ridgeway, Hayes, 9 March 2016.
Marchantia polymorpha subsp. ruderalis, Common Liverwort.   Ridgeway, Hayes, 9 March 2016.
As its common name suggests, Marchantia polymorpha is easy to find.  It grows on the untrampled edges of roads and pavements, and this patch is on the ground behind a street name sign.

The circular features are cups containing gemmae, little asexual reproductive buds which can be splashed out by raindrops.

Marchantia polymorpha subsp. ruderalis, Common Liverwort.   Gemmae in cups.  Ridgeway, Hayes, 9 March 2016.
Marchantia polymorpha subsp. ruderalis, Common Liverwort.   Gemmae in cups.  Ridgeway, Hayes, 9 March 2016.
This simple system allows the liverwort to spread very easily. 

Here's a related species:

Lunularia cruciata, Crescent-cup Liverwort.  Husseywell Park, Hayes, 8 April 2016.
Lunularia cruciata, Crescent-cup Liverwort.  Husseywell Park, Hayes, 8 April 2016.
This Crescent-cup Liverwort is on a water inlet pipe in a small park.  As you can see, this one has gemmae in crescent-shaped organs:

Lunularia cruciata, Crescent-cup Liverwort.  Gemmae in crescents.   Husseywell Park, Hayes, 8 April 2016.
Lunularia cruciata, Crescent-cup Liverwort.  Gemmae in crescents.   Husseywell Park, Hayes, 8 April 2016.
 These serve exactly the same function as the round cups on Marchantia polymorpha.

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