Moss (蘚)

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Moss(es) are simple plants not differentiated ( = specialised, 分化, 特殊化) into true root, stem and leaf.

They do not possess vascular tissues, the special conductive tissues of xylem and phloem. Hence, they can not support themselves well on land and are inefficient in transport. However, they do bear simple leaves and water-absorbing rhizoids (root-like structures).

They live in moist and shady place, and are dependent on water as the medium of sexual reproduction. The male sex cell (a motile sperm), has to swim in the thin water film on plant surface to meet the female sex cell (a non-motile egg cell) before successful fertilisation.

The photograph shows an aerial view of a colony of mosses which probably belongs to the genus Polytrichum.

Another specimen is shown below.