Botanical enthusiasts smile skeptically as they listen to the legends of the night on Ivan Kupala. How can I find a fern flower? Who invented this? How can one find something that never existed in nature?
Many nature lovers divide plants into flowering and non-flowering species. Non-flowering plants are called spore plants, examples of which will be considered in the article today.
Spore Plants: First Acquaintance
Let's start the acquaintance with a short description. The word "dispute" came to us from the Greek language. Translated, it means "seed" or "seed." It is a very small formation, the size of which is about 1 micron.
Spore plants formed a very long time ago. In fact, they are direct descendants of the flora that came from the ocean to land. Spore plants include more than fern. Scientists divide them into two categories: higher and lower. In the first category - ferns, crowns, moss and horsetail. In the second - algae and lichens.
Spore Plant Life Cycle
If we talk about higher spore organisms, then they have a very interesting life cycle. Here you can see the alternation of asexual and sexual species. Accordingly, reproduction, depending on the species, is sexual or asexual. The full life cycle is continuous. The plant forms a gametophyte (an organ of sexual reproduction) and a sporophyte (an organ of asexual reproduction).
Evolution allowed these types of plants to develop in two directions. The result was two broad groups: haploid and diploid. Describing spore plants, examples of the haploid group of which are mosses, scientists have proved that they have a more developed sexual gametophyte. The sporophyte in the haploid group has a subordinate status. The diploid direction of spore organisms (horsetail and ferns) has a highly developed sporophyte, and the gametophyte in the form of a sprout.
The sexual generation always has anteridia and archegonia. These are male and female organs. Male sperm are motile, female reproductive cells are static. To fertilize it, the sperm must enter the aquatic environment, through which it can reach the target. A fertilized egg forms an embryo from which an asexual generation, that is, a sporophyte, sprouts. The next stage of reproduction will occur by spores that develop in sporangia.
Features
Not everyone knows how to distinguish spore plants. Examples of discussions on this topic may look like this:
- Spore plants do not bloom. This species is not biologically capable of flowering.
- Have a unique life cycle. Sexual and asexual reproduction.
- The impossibility of sexual fertilization without the presence of water.
If three characteristics are inherent in the plant in question, then this is a spore species.
Spore Plants: Ferns
It is hard to find someone who has never seen a fern. This ancient plant is used to decorate parks and garden plots. Indoor species of ferns are grown in flowerpots, and lovers of forest walks have seen lush and green fern thickets many times.
All ferns are dominated by cirrus dissected complex leaves. These spore plants (ferns) have the most noticeable sporangia. The location of these organs is the underside of the leaves.
For information, we add that there are more than ten thousand ferns in nature. All this diversity is combined in 300 genera.
The structure of spore plants on the example of mosses
Mosses can be attributed to the most primitive species of higher plants. All bryophytes are small-sized representatives without conductive tissue. The division into the stem and leaves of mosses is conditional. These amazing spore plants are examples of the ability to adapt to environmental conditions.
So, the body of the moss is conditionally divided into a stem, leaves and roots. Yes, the roots of this plant are replaced by filiform outgrowths - rhizoids. Their main difference from the true roots is the absence of conductive tissue. In moss, each rhizoid is one or more living cells.
Mosses feel good in marshy places, in the shade or just in damp. Mosses actively evaporate moisture, but make up for the loss of the entire surface of the plant. Despite the fact that spore plants need water to reproduce, some species of mosses are able to wait for periods of drought, they even adapted to survive on rocky sites. How this happens is not completely clear.
The dominant generation of mosses is the sexual. Sporophyte is completely dependent on the gametophyte.
Spores cannot form on the leaves, like ferns, since the leaves themselves are very arbitrary. For these purposes, the mosses have adapted a spore box, towering above the gametophyte on the leg-string.
A feature of mosses is the possibility of vegetative propagation. The kidneys and nodules are involved in this process. If the vegetative part is separated from the main plant, then it develops into an independent individual.
A bit about lower species
We will not list all lower spore plants. Examples that are interesting to describe are algae. These plants are not as numerous as ferns and lichens; there are a little more than a hundred of them. The habitat of this flora is water. Algae do not have leaves and roots. They are attached to the ground or stones with transparent hooks. Algae is divided into 11 departments, 4 of which people have learned to use for their own purposes.