What are the structural features of mosses? In their structure, they resemble algae, but, unlike them, most species of mosses have a stem and leaves. Rhizoid-like roots help them stay on the surface and absorb water. Mosses are characterized by a fairly wide range of habitats. Most of them prefer moist, shady places, often around the base of trees. But there are those who love light, and grow as epiphytes on tree branches or in open areas, such as clay banks and the edges of paths. All sphagnum or peat mosses grow on lakes and swamps, where there is stagnant water all year round.
Appearance
Most mosses are small, green leafy plants attached to soil, tree bark, or stones with thin, threadlike roots called rhizoids. Some species may have single erect stems, while others have branching stems and resemble a soft green carpet covering the soil. In New Zealand, the tallest moss grows (Dausonia superba), reaching a height of half a meter, but most species reach about 1-2 centimeters in height.
Harsh Survival
Real masters of suspended animation, such as mosses, can withstand the action of high temperature (up to 70 ° C) for a long time, and with the return of moisture they come back to life again. This amazing life form will grow in deep, dense forests and caves, where the light intensity is insufficient for the favorable growth of any other green plant. In the high latitudes of the Arctic, mosses are one of the few plant forms that can survive the destructive cold. Many species can favorably exist in inaccessible cracks and crevices where most plants simply could not survive. They do not die even when they dry. In dry periods, their metabolism is turned off until the rains return, when their processes are restarted, and all vital functions are restored. The structural features of the mosses help in this. These primitive plants are considered one of the first to develop the ability to live on land.
Ubiquitous disputes
Issued spores of mosses are able to travel long distances downwind and remain viable for decades. After finding comfortable conditions, they settle and begin to produce hairy filaments. Threads sprout from spores, which are attached to the surface with the help of rhizoids. The structure of the moss is represented by a gametophyte, which includes the stem and leaves, where the photosynthesis process takes place, during which sunlight is converted into nutrient energy. What are the structural features of mosses? Mosses do not have full leaves; instead, tiny processes in the form of flat scales or flakes are arranged on a stalk in a spiral.
Mosses: structure and reproduction
Although mosses do not bloom, in some species shoots with male genital organs may look like small green flower heads. Reproduction takes place in the open, it is not hidden inside the flowers. Anterozoids are released into small bags in order to fertilize the egg of neighboring cells. There is a spore capsule in the stem called sporangia; it can release up to a million spores. Ripening occurs under a special coating that dries and falls off when it is no longer necessary. Mature spores are released and leave the capsule to form new plants.
Mosses do not depend only on sexual reproduction. Gametophytes have balls of non-specialized cells attached to them. If one of the side obegs breaks off, then one simple cell is enough to form a new one. This ensures the survival of the plant under adverse conditions. The structural features of mosses, the simplicity of construction and several breeding methods allow them to find their habitat everywhere from the Arctic Circle to the equator. These are surprisingly stable and versatile plants.
Biology and Evolution
There is an assumption that mosses are a common ancestor of all terrestrial plants. Modern science identifies more than 10,000 species adapted to a wide variety of habitats, from water bodies to the desert. Despite the fact that the structure of moss is structurally simple, gametophytes contain different types of cells. In response to dehydration, cells resume cell division and differentiate into thick-walled, contracted cells that undergo programmed cell death. Life resumes after the plant is in favorable conditions. Mosses managed to preserve the primitive aspects of the cellular structure and composition, as well as an amazing ability to adapt, which allowed them to populate a variety of habitats.
Structure Features
What are the structural features of mosses? The structure includes the stem, leaves, axillary hair and rhizoids. The stem, as a rule, consists of small thick-walled epidermal cells, thin-walled parenchyma cells and conductive cells. Conducting cells include hydroids and leptoids. Leaves, as a rule, consist of one layer of cells, with the exception of the vein and fields, which may consist of several layers of differentiated cells. On the stem there is sporophyte, sporangia, spores, which also consist of specialized types of cells.
Moss Structure Benefits
What are the structural features of mosses, we have already found out, now we should consider their structural advantages. Since mosses get all the nutrients from the air, since they do not have real roots, these unpretentious plants require only shade, acidic soil and sufficient moisture. The preferred habitat is low-fertile soil with a low content of nutrients in the water. In addition to good adaptability, mosses have a good ability to produce large volumes of tissue, consisting of one type of cell, as well as rapid regeneration of protoplasts in the cell wall.
Kukushkin flax
The structure of moss Kukushkin flax is represented by thin brownish stems densely covered with small dark green leaves. This perennial plant often covers damp places with a dense carpet, used for medical purposes. Kukushkin flax grows in the tundra, in swamps, in the mountains, forests and meadows. It forms a cushion of turf or merges into one continuous dense canopy. Perennial leaf stems of moss are quite large in size. In the lower part of the stem rhizoids develop (a primitive analogue of the roots).
Next is the main horizontal stem without leaves. Then, a secondary upright stalk up to 15 cm long is formed. Individual specimens can reach 30 cm. The secondary stalk densely covers the similarity of leaves. The internal structure of cuckoo moss is represented by a primitive vascular system through which water and nutrients move along the stem to the leaves. Some stem cells are elongated and paired, designed exclusively for transporting water. The lower leaves on the stem do not develop, but remain in the form of scales.