They don't have roots. Instead they have thin root-like growths called rhizoids that help anchor them. Because they don't have roots and stems to transport water, mosses dry out very quickly, so they are usually found in moist habitats. The only place they don't grow is in salt water. Moss plants are usually very small. They have leaf-like structures or phyllids that are usually only a single cell layer thick. The phyllids spiral around a stem-like structure called the caulid.
Mosses reproduce in an unusual way. There is a first generation moss, the gametophyte. The gametophyte produces a sperm and an egg. They date back million years, and have survived and thrived through a range of drastic climate changes. Comprised of 15, — 25, species, they occur on every continent and in every ecosystem habitable by plants that use sunlight for energy.
Among the world of plants, the bryophytes are the second most diverse group exceeded only by the angiosperms, the flowering plants , species. Instead they have rhizoids, which are small hairlike structures. Their main function is anchoring the plant to rock, bark or soil. So without roots, some moss suck nutrients up through the rhizoids and others draw in moisture and minerals from rain and the water around them through their highly absorbent surfaces.
Because of their range of adaptations, they are able to occupy areas that are otherwise uninhabitable such as rocky ledges on mountainsides. Different species have adapted to survive in extreme conditions. In hot environments like prairies or deserts, one way that mosses tolerate heat is by becoming dormant. When they're desiccated dried out they can survive heat much better than when they're hydrated. That's a resilient little plant right there. They help to soak up rainfall, maintain moisture in the soil below and keep conditions around them humid.
This enables other plants around them thrive, such as in habitats like marshes and woodland. Mosses also play a vital role in the development of new ecosystems.
They're among the first plant colonisers of disturbed sites, such as when an area is deforested or affected by forest fires. They stabilise the soil surface and retain water, helping new plants to grow. Most of us do not automatically think of the plants that grow on rocks, rooftops, concrete, and any other moisture-laden area; however, this opportunistic bunch, choosing many eclectic substrates, exists. Their leaves are mostly one cell thick, they have no true roots, stems, flowers, or fruit, and instead of seeds they have spores.
For more information, read on, and consult Richardson Schofield , Shaw and Goffinet , and Sterling For in-depth information on the ecology of mosses, see Janice Glime's online book, Bryophyte Ecology. How do mosses reproduce and spread? Mosses spread in multiple ways, but unlike flowering plants, they depend on moisture to sexually reproduce. Mosses reproduce by spores, which are analogous to the flowering plant's seed; however, moss spores are single celled and more primitive than the seed.
Spores are housed in the brown capsule that sits on the seta. As the spores ripen they are dispersed from the capsule, and some land in areas where there is enough moisture for them to grow.
The young moss looks like a very thin tangled mass of branching green hairs. Buds will appear next on the green hairs, from which tiny stalks and slim leaves will grow. Some mosses have cups on their tops that produce sperm, these are male plants. The female counterpart has eggs between her overlapping leaves. Water is a necessity for fertilization; as the sperm become mature they have to swim to the eggs to fertilize them. The fertilized egg then produces the stalked brown capsule.
Mosses also spread asexually by sending out new shoots in the spring from last years plants as well as fragmentation. Pieces of the moss body can break off, move by wind or water, and start a new plant if moisture permits. How do Mosses Acquire Nutrients? Mosses also have different mechanisms they use for acquiring nutrients.
Some mosses are able to take up nutrients from water flowing over them, thus they have very effective absorptive surfaces. Other mosses, such as Polytrichum , sequester nutrients directly from the soil or substrate on which they are growing and transfer the nutrients to their growing tips.
With this in mind we can see that the physical and chemical nature of the substrate as well as its water holding capacity are extremely important in establishment of mosses.
Where do mosses live?
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