The gametophore represents the mature gametophyte as it produces male and female sex organs and gametes. The male sex organs produce sperm and are called antheridia , while the female sex organs produce eggs and are called archegonia. Water is a 'must-have' for fertilization to occur. Sperm must swim to archegonia in order to fertilize the eggs. Fertilized eggs become diploid sporophytes, which develop and grow out of the archegonia. Within the capsule of the sporophyte, haploid spores are produced by meiosis.
Once mature, the capsules open releasing spores and the cycle repeats again. Mosses spend the majority of their time in the dominant gametophyte phase of the life cycle. Mosses are also capable of asexual reproduction. When conditions become harsh or the environment is unstable, asexual reproduction allows mosses to propagate faster.
Asexual reproduction is accomplished in mosses by fragmentation and gemmae development. In fragmentation, a piece of the plant body breaks off and eventually develops into another plant. Reproduction through gemmae formation is another form of fragmentation. Gemmae are cells that are contained within cup-like discs cupules formed by plant tissue in the plant body.
Gemmae are dispersed when raindrops splash into the cupules and wash gemmae away from the parent plant. Gemmae that settle in suitable areas for growth develop rhizoids and mature into new moss plants. Liverworts are non-vascular plants that are classified in the division Marchantiophyta. Their name is derived from the lobe-like appearance of their green plant body thallus that looks like the lobes of a liver.
There are two main types of liverworts. Leafy liverworts closely resemble mosses with leaf-like structures that protrude upward from the plant base.
Thallose liverworts appear as mats of green vegetation with flat, ribbon-like structures growing close to the ground. Liverwort species are less numerous than mosses but can be found in almost every land biome. Though more commonly found in tropical habitats, some species live in aquatic environments, deserts , and tundra biomes.
Liverworts populate areas with dim light and damp soil. Like all bryophytes, liverworts do not have vascular tissue and acquire nutrients and water by absorption and diffusion.
Liverworts also have rhizoids hair-like filaments that function similarly to roots in that they hold the plant in place. Liverworts are autotrophs that require light to make food by photosynthesis.
Unlike mosses and hornworts, liverworts do not possess stomata that open and close to obtain carbon dioxide needed for photosynthesis. Instead, they have air chambers below the surface of the thallus with tiny pores to permit gas exchange. Because these pores can not open and close like stomata, liverworts are more susceptible to drying out than other bryophytes. As do other bryophytes, liverworts exhibit alternation of generations.
The gametophyte phase is the dominant phase and the sporophyte is totally reliant on the gametophyte for nutrition. The plant gametophyte is the thallus , which produces male and female sex organs. Male antheridia produce sperm and female archegonia produce eggs. In certain thallose liverworts, archegonia reside within an umbrella-shaped structure called an archegoniophore. Water is required for sexual reproduction as sperm must swim to archegonia to fertilize the eggs.
A fertilized egg develops into an embryo, which grows to form a plant sporophyte. The sporophyte consists of a capsule that houses spores and a seta short stalk. Spore capsules attached to the ends of seta hang below the umbrella-like archegoniophore. When released from the capsule, spores are dispersed by wind to other locations. Spores that germinate develop into new liverwort plants. Liverworts can also reproduce asexually through fragmentation plant develops from a piece of another plant and gemmae formation.
Gemmae are cells attached to plant surfaces that can detach and form new individual plants. Hornworts are bryophytes of the division Anthocerotophyta. The State Herbarium holds very significant collections of these groups. Our handbooks on South Australian lichens, mosses, fungi and algae are based on these collections.
Southern Australian oceans are amongst the world's most biodiverse marine algal regions, particularly for red algae which flourish in deeper waters. The State Herbarium's collections of green, red and brown algae are very extensive and includes the specimens used by Professor HBS Womersley in compiling the six volumes of the Marine Benthic Flora of Southern Australia. The Phycology Unit is undertaking research on these plants. The Bryophytes, comprising mosses, liverworts and hornworts, are distinct groups of non-vascular plants which are very ancient in their origins.
Some groups have complex and fascinating morphological adaptations to their environment, and some have even evolved a form of vascular system. Research on mosses being undertaken at the State Herbarium is contributing towards the Flora of Australia project, especially in the families Pottiaceae and Bartramiaceae.
Bryophytes along with lichens play an important role in arid ecosystems as components of the critical but fragile crusts that stabilise many arid soils. The State Herbarium collection is particularly rich in arid soil crust species of bryophytes and lichens, notably a large collection from the research of Dr RW Rogers.
The fungi, with about 1. The Difference Between. See Answer. Best Answer. Hope that helps. Study guides. Q: Importance of non vascular plants Write your answer Related questions. What is the importance of vascular and non vascular plants?
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