divisionsBryophyta

Divisions Bryophyta, commonly known as true mosses, are a division (phylum) of non-vascular land plants that includes the majority of moss species. They are small, green, and often form dense mats or cushions in moist habitats such as forest floors, stream banks, and bogs. Unlike many vascular plants, bryophytes lack true xylem and phloem; their body is typically composed of simple leafy shoots or filaments anchored by rhizoids.

Life cycle and morphology: Bryophyta exhibits alternation of generations with a dominant haploid gametophyte stage, which is the leafy, photosynthetic form. The gametophyte produces antheridia (male) and archegonia (female). Sperm require free water to swim to the egg, enabling fertilization. The resulting diploid zygote grows into a dependent sporophyte, which bears a sporangium (capsule) that releases haploid spores to form new gametophytes. Reproduction can also occur asexually by fragmentation or gemmae.

Taxonomy and diversity: The division Bryophyta comprises true mosses, with an estimated 12,000 species globally. In many taxonomic systems, mosses are organized within class Bryopsida, while liverworts and hornworts are placed in separate divisions, Hepaticophyta and Anthocerotophyta. The group is diverse in habit and habitat, ranging from prostrate mats to erect tufts and spanning a wide range of moisture and light conditions.

Ecology and significance: Mosses contribute to moisture retention, soil formation, and carbon cycling, and serve as habitat and food sources for a variety of microorganisms and invertebrates. Some mosses, such as peat mosses, play notable roles in ecosystem processes in wetlands.