Our object of interest is the moss Physcomitrella patens ssp. patens,
in the remainder of the text called 'moss' or 'Physcomitrella'.
Some images of moss culture on plates:
Here you can have a detailed look at the gametophore ('moss plant')
with close-ups of the phylloids ('leaves'):
All images were taken using a cryo-SEM at the
REM-Labor of the
University of Basel.
Together with the ferns (Pteridophyta) and the seed(-bearing) plants
(Spermatophyta), mosses (Bryophyta) belong to the Embryophyta. Whereas
in seed plants the diploid spermatophore is dominant, in mosses this part
belongs to the haploid gametophore. To learn about the life cycle of
Physcomitrella click on the thumbnail:
Comparison of seed plants and mosses:
Cauloid Shoot
Phylloid Leaf
Rhizoid Root
Mosses, like seed plants, possess a (thin) cuticula, cellulose,
stoma, chlorophyll a and b and carotenoids - they are land plants.
However, they do neither have vascular bundles nor lignin.
Some interesting things about mosses:
They can regenerate very well from every part of the plant.
They can survive long times of dryness (up to 14 years), extreme cold
(antarctica) and heat (70 to 110 degrees Celsius).
They can live with only 0.1% of sun light (seed plants need at least 2%).
(There is of course no single moss that possesses all this
features.
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