Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Although non-vascular plants lack these particular tissues, many possess simpler tissues that have specialized functions for the internal transport of water. Non-vascular plants include two distantly related groups: Bryophytes, an informal group that taxonomists treat as three separate land-plant Divisions , namely: Bryophyta (mosses), Marchantiophyta (liverworts), and Anthocerotophyta (hornworts). In all bryophytes, the primary plants are the haploid gametophytes, with the only diploid portion being the attached sporophyte, consisting of a stalk and sporangium. Because these plants lack lignified water-conducting tissues, they can't become as tall as most vascular plants. Algae - especially the green algae. The algae consist of several unrelated groups. Only those groups of algae included in the Viridiplantae are still considered relatives of land plants. These groups are sometimes called as "lower plants", referring to their status as the earliest plant groups to evolve, but the usage is imprecise, since both groups are polyphyletic and may be used to include vascular cryptogams, such as the ferns and fern allies that reproduce using spores. Non-vascular plants are often among the first species to move into new and inhospitable territories, along with prokaryotes and protists, and thus function as pioneer species. Non-vascular plants do not have a wide variety of specialized tissue types. Mosses and leafy liverworts have structures called phyllids that look like leaves, but are not true leaves because, except in the Polytrichaceae they are single sheets of cells with no internal air spaces no cuticle or stomata and no xylem or phloem. Consequently, phyllids are unable to control the rate of water loss from their tissues and are said to be poikilohydric. Some liverworts, such as Marchantia have a cuticle and the sporophytes of mosses have both cuticles and stomata, which were important in the evolution of land plants.
Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water. Non-vascular plants include two distantly related groups: Bryophytes, an informal group that taxonomists treat as three separate land-plant divisions , namely: Bryophyta (mosses), Marchantiophyta (liverworts), and Anthocerotophyta (hornworts). In all bryophytes, the primary plants are the haploid gametophytes, with the only diploid portion being the attached sporophyte, consisting of a stalk and sporangium. Because these plants lack lignified water-conducting tissues, they can't become as tall as most vascular plants. Algae , especially the green algae. The algae consist of several unrelated groups. Only the groups included in the Viridiplantae are still considered relatives of land plants. These groups are sometimes called "lower plants", referring to their status as the earliest plant groups to evolve, but the usage is imprecise, since both groups are polyphyletic and may be used to include vascular cryptogams, such as the ferns and fern allies that reproduce using spores. Non-vascular plants are often among the first species to move into new and inhospitable territories, along with prokaryotes and protists, and thus function as pioneer species. Non-vascular plants do not have a wide variety of specialized tissue types. Mosses and leafy liverworts have structures called phyllids that resemble leaves, but only consist of single sheets of cells with no internal air spaces no cuticle or stomata and no xylem or phloem. Consequently, phyllids are unable to control the rate of water loss from their tissues and are said to be poikilohydric. Some liverworts, such as Marchantia have a cuticle and the sporophytes of mosses have both cuticles and stomata, which were important in the evolution of land plants.
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