Moss microscopic plants collapsed after only ten days of cultivation. Why?

In fact, it is a lower higher plant. Because of the definition of higher plants: differentiated tissues and organs, multicellular reproductive organs, zygotes develop into embryos (young sporophytes) in the mother.

Moss has the differentiation of roots and leaflike bodies (moss, hornworts) or roots and leaves (moss), and the reproductive organs are multicellular sperm organs and stem-egg organs, which form embryos after fertilization and temporarily parasitize the mother.

Algae, fungi and lichens have no real differentiation of roots and leaves, so they are called lower plants.

Bryophytes, ferns and seed plants are higher plants with root and leaf differentiation.

Both ferns and seed plants have vascular bundles, which are evolved conducting tissues, so they are called vascular plants.

Therefore, bryophytes are higher plants, but they belong to the lower group of higher plants. Typical lower plants are various algae. Although some algae have stem-leaf differentiation and a few algae have multicellular reproductive organs, zygotes will never form embryos.