Because all bryophytes have no vascular bundle structure, their water transport ability is not strong, which limits their size and height. There are false roots, but no real roots. The leaves are composed of monolayer cells, and the degree of cell differentiation of the whole plant is not high, which is low in the plant kingdom.
One more thing, just like going upstairs, you need to rely on water to breed. The main part of bryophytes is gametophyte, which can produce gametes (sex cells). Gametophytes can form male and female reproductive organs. When the male genitals mature, the sperm is released, and the sperm swims into the female genitals with water as the medium to fertilize the eggs. The fertilized egg develops into sporophyte.
Moss grows under clean water and is not polluted. It is rich in green pigment, lutein, carotene, vitamins B 1, B2, B 12, vitamin C and vitamin D, and also contains inorganic salts and trace elements needed by human body. Can prevent and treat malaria, and has certain curative effect on dyspepsia, pneumonia and tracheitis. It is a natural green and healthy food.