The kingdom of plants is divided into two types: the highest, real seaweed and red seaweed. The last two types informally unite in one group under the name the lowest plants as they have similar characteristics in comparison with the land highest. Differences between types are shown in everything: appearance, structure of a body, food, habitat.
The lowest plants
The informal group of the lowest plants unites subkingdoms a bagryanok, or red seaweed, and the real seaweed. Both those and other mainly sea inhabitants, than, first of all, differ from the land higher plants widespread on a land surface. Earlier the lowest plants called all organisms which were not animal or usual land plants: that is not only seaweed, but also mushrooms, bacteria, lichens.
Today definition of the lowest plants much more exact: these are those plants which have no differentiated structure of the body, that is are not dismembered on several parts. This their second main difference from the highest subkingdom. All species of seaweed are uniform: they do not allocate leaves, escapes, roots, flowers. They consist of an identical body in all parts.
The lowest plants are monocelled and multicellular, and their sizes can vary from invisible with the naked eye to huge, in several dozen meters in length. The lowest plants – more ancient in comparison with the more developed relatives: the oldest remains of these organisms have age about three billion years.
The higher plants
The higher plants grow mainly on the land though there are also not numerous exceptions. They have the complex structure of fabrics allowing them to conduct richer life: they developed the mechanical, integumentary, carrying-out fabrics. It is explained by accommodation of plants the land: air, unlike water, less comfortable habitat – it is necessary to protect itself from drying, to provide heat exchange, to gain a foothold strongly in one place. Parts of the body of these organisms perform various functions and have the different building: the root gains a foothold in the earth and provides water and mineral food, stalks transport the substances received in the soil on all body of a plant, and leaves are engaged in photosynthesis, turning inorganic compounds into organic. Fine integumentary fabric protects a body at the expense of what the higher plants are considered as more resistant to environmental conditions. This property is provided with also thick cellular walls with lignin – they protect stalks from mechanical damages. The higher plants, unlike the lowest, have multicellular bodies of reproduction which besides are better protected by dense walls. Bryophyta (all species of mosses) and vascular which are divided into sporous and seed belong to this subkingdom.