The moss Physcomitrella patens

Our object of interest is Physcomitrella patens ssp. patens, the spreading earthmoss. In the remainder of the text called 'moss' or 'Physcomitrella'. Together with the ferns (Pteridophyta) and the seed(-bearing) plants (Spermatophyta), mosses (Bryophyta) belong to the Embryophyta.

More images:


The Physcomitrella patens gametophore ('moss plant') is the haploid organism that develops from a haploid spore that has one set of chromosomes. Image: With kind permission from the REM-Labor, University of Basel, Switzerland
The Physcomitrella patens sporophyte is the diploid multicellular stage which develops from the zygote after a haploid egg and a haploid sperm merged. It contains a double set of chromosomes, one set from each parent. Photo: licensed under Creative Commons Attribution-ShareAlike 3.0 Unported License. Source: ReskiLab, University of Freiburg. http://www.plant-biotech.net
Close-up of the Physcomitrella patens phylloid ('leave'). Image: With kind permission from the REM-Labor, University of Basel, Switzerland
Another detail of the moss phylloid ('leave'). Image: With kind permission from the REM-Labor, University of Basel, Switzerland
The socalled protonema is a chain of cells of the earliest stage of the haploid phase of a bryophyte life cycle. Photo: licensed under Creative Commons Attribution-ShareAlike 3.0 Unported License. Source: ReskiLab, University of Freiburg. http://www.plant-biotech.net