Key Difference – Thallophyta vs Bryophyta
According to the earliest classification of the plant kingdom, there were two sub-kingdoms; Cryptogamae (seedless plants) and Phanerogamae (seed-bearing plants). The sub-kingdom Cryptogamae is further divided into three divisions, namely; Thallophyta, Bryophyta, and Pteridophyta. According to this classification, both Thallophyta and Bryophyta include very primitive plants with no seeds and hidden reproductive structures. The key difference between them is that, in thallophytes, the body is a thallus and not differentiated into stems, leaves, or roots whereas, in bryophytes, though the body is not well-differentiated, they may have stem-like and leaf-like structures. However, the division Thallophyta lately removed from the Kingdom Plantae and put into a different Kingdom called Protista, due to lack of certain features, which are common to green plants. Some of these features include lack of differentiation of plant body, the presence of unicellular sex organs and zygotes, etc. In this article, the difference between division Thallophyta and Bryophyta will be discussed in more detail.
What is Thallophyta?
Division Thallophyta characterized by the presence of undifferentiated body with no distinctive stems, roots, and leaves. Hence, the body of these plants is called a thallus. Thallophytes do not have a vascular system, unlike the higher green plants. This division mainly includes the algae, which mainly exist in aquatic habitats and are capable of photosynthesis. Some examples of this division include Ulva, Cladophora, Spirogyra, Chara, etc. The sex organs of most thallophytes are unicellular. Thallophytes both sexual and asexual reproduction methods. The life cycle of thallophytes has two independent gametophytic and sporophytic generations. Asexual reproduction occurs especially during unfavorable conditions through the spores called mitospores.
Spirogyra, a kind of algae
What is Bryophyta?
Bryophytes are the most primitive green plants according to the latest classification of plant Kingdom. These plant bodies do not have true leaves, stems, roots or vascular system. Bryophytes include the mosses, liverworts, and hornworts. The body of these plants can grow up to 15 cm long. Mosses have rhizoids, which help to anchor and absorb nutrients. Bryophytes contain chlorophyll, and thus capable of photosynthesis. The life cycle of bryophytes has two generations; gametophyte and sporophyte. Bryophytes are usually found in moist terrestrial habitats because they need water to transport their sperms. Asexual reproduction is also seen.
A Bryophyta Species
What is the difference between Thallophyta and Bryophyta?
Structure:
Thallophytes: In thallophytes, the body is a thallus and not differentiated into stems, leaves or roots.
Bryophytes: In bryophytes, the body is not well-differentiated but may have stem-like and leaf-like structures. The body can be grown up to about 15 cm height.
Presence of Rhizoids:
Thallophytes: Thallophytes do not have rhizoids.
Bryophytes: Bryophytes have rhizoids.
Examples:
Thallophytes: Thallophytes include green algae.
Bryophytes: Bryophytes include liverworts, mosses, and hornworts.
Habitat:
Thallophytes: Thallophytes are mainly aquatic.
Bryophytes: Bryophytes are mainly found in terrestrial habitats with lots of moisture.
Zygote:
Thallophytes: In thallophytes, the zygote is unicellular.
Bryophytes: In bryophytes, the zygote is multicellular.
Asexual Reproduction:
Thallophytes: In thallophytes, asexual reproduction occurs via spores called mitospores.
Bryophytes: In bryophytes, asexual reproduction may occur via tissues parts (Ex: liverworts).
Reproduction Organs:
Thallophytes: Reproduction organs of thallophytes are unicellular.
Bryophytes: Reproduction organs of bryophytes are multicellular.
Image Courtesy:
1. 3×2 millimeters of Spirogyra By Bob Blaylock at English Wikipedia [CC BY-SA 3.0 or GFDL], via Wikimedia Commons
2. Unknown Bryophyta closeup By Jeff Turner from Santa Clarita, CA, United States (Deciduous Tree Fungi) [CC BY 2.0], via Wikimedia Commons
