Higher plants , or land plants , or embryophytes ( lat. Embryophyta , sometimes the Latin name Plantae sensu strictissimo is used - "plants in the narrowest sense"), a treasure of green plants that are characterized by tissue differentiation , in contrast to lower plants - algae . Higher plants include bryophytes and vascular plants ( fern - shaped , fluff- like , gymnosperms and angiosperms ).
| Higher plants | |||||||||
 Psilotum ( Psilotum ) | |||||||||
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Embryophyta Engler , 1886, | |||||||||
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Higher plants in some classification systems are considered as taxa of a rank from sub-kingdom to sub - department .
The evolution of higher plants is closely related to land access and the conquest of land niches .
The development of specialized tissues was an important condition for the plants to land. For a comfortable existence in the air, plants needed to develop at least epidermis with stomata to protect against drying and heat transfer and conductive tissues for the exchange of mineral and organic substances . The output of plants on land also resulted in the division of the plant organism into the root , stem and leaf .
A wide variety of living conditions of terrestrial life explains the extreme richness of plant forms. But despite the diversity of appearance, all higher plants are characterized by one type of reproductive process ( oogamy ) and two variants of one type of change of nuclear phases, or “change of generations” (heteromorphic developmental cycles with a predominance of either sporophyte or gametophyte ). In all cases, both “generations” — the gametophyte and sporophyte — differ morphologically, cytologically, and biologically. In the evolution of almost all departments of higher plants (except bryophytes), sporophyte predominates in the developmental cycles.
Content
Mosses
Among the higher plants, the Bryophyta sensu lato has the most primitive structure - they have no root (there are rhizoids ), and the marchantium , antocerot, and some Jungermannian mosses do not divide into leaf and stem - they are thallus like algae or lichen . The oral apparatus is extremely primitive, the conductive system is not developed, the parenchyma performs the conductive functions.
Vascular Spore
The so-called Vascular spore , which include ferns , horsetails , plunders and psilots , have a fairly developed conducting system, the stem, leaf and root are always expressed. However, they are still strongly associated with the aquatic environment, since they have a free-living gametophyte and sexual reproduction in them occurs with the participation of flagellate spermatozoa , which cannot exist outside the aquatic environment.
If Bryophytes and Vascular Spore are considered as a single group, the collective term “ higher spore plants ” is sometimes applied to it [1] .
Seed Plants
An important evolutionary breakthrough of plants on the path to conquering land was the appearance of the seed and shell of pollen grains. Due to the fact that from now on the gametophyte (now consisting of only a few cells) began to completely fit inside the moisture-retaining shell, plants were able to master desert and cold areas.
In some gymnosperms and almost all flowering plants, vessels and sieve tubes appear in the conductive structures - hollow conductive elements consisting of the walls of dead cells, due to which their conductive systems are extremely effective.
Gnetum , gymnospermous plant with vessels in the conducting system
Trochodendron , a flowering plant primarily vascularless
Sciona , one of the few higher plants that managed to return to the sea
Notes
- ↑ Korovkin O. A. Anatomy and morphology of higher plants: a glossary of terms. - M .: Drofa, 2007. - S. 33. - 268, [4] p. - (Biological Sciences: Dictionaries of Terms). - 3000 copies. - ISBN 978-5-358-01214-1 .
Literature
- Elenevsky A.G. Botany. Systematics of higher, or terrestrial, plants: textbook. for stud. higher ped textbook. Institutions / A. G. Elenevsky, M. P. Solovyov, V. N. Tikhomirov. - Ed. 4th, rev. - M .: Publishing Center "Academy", 2006. - 464 p. - 3000 copies. - ISBN 5-7695-2141-4 . - UDC 596 (075.8)