It seems to thrive on areas previously treated with Glyphosphate and gravel/limestone. Possibly due to phosphate take up. (any chemists/biologists have a view?) It is also as old as time and has the same/similar optical light sensors we have at the back of our eyeballs. It is resistant to heat and cold and is very difficult to get rid of. Sigh. Re posts above it is apparently edible. full of protein and possibly has health benefits including anti inflammatory effects, yuck. Washing soda is alleged to be effective after repeated applications, covering in plastic sheet or dosing with salt. Moss/Algea killer available in other countries works but I am not sure that this is available or permitted within EU area.
At least I now know that there is not some strange beast active in my garden at night.
It's gly
phosate, not gly
phosphate, which is just a proprietary name, no phosphate involved (it's
N-(phosphonomethyl)glycine either as a free acid, or an amine salt, fact fans). It can offer a significant source of phosphorus to anything it doesn't kill.
Nostoc is an extremophilic, colony forming cyanobacteria (not really an algae). They're ubiquitous. When you clear any ground of vegetation with a broad-spectrum herbicide you create nice opportunities for anything with resistance and, as mentioned, glyphosate is a good source of vital phosphorus. It'll dry out and 'disappear' if not wet and indeed, some people eat them, though I'd skip it unless it was a choice of that or KFC. They're good for soil as they fix nitrogen. Just scoop it up and throw it away, trying to kill it is not worth the effort given it's everywhere.
Very common on gravel driveways etc, as the surface area forms a nice substrate for the colonies.