Relics are organisms that have survived on Earth in certain territories since antiquity, despite the changing conditions of existence. They are the remains of ancestral groups, widespread in past geological eras. The word "relict" comes from the Latin reliquus, which means "remaining."
Relic plants and animals are of great scientific value. They are information carriers and can tell a lot about the natural environment of past eras. Let's get acquainted with plant organisms classified as relic.
Geographical relic plants
Geographical relic plants include species preserved in a certain region as the remainder of past geological eras, in which the conditions of existence were significantly different from modern ones. So, Neogene (tertiary) relics include forest-forming tree species (chestnut, dzelkva, and some others), a number of evergreen shrubs (Colchis weevil, boxwood, prickly needle, Pontic rhododendron, etc.), as well as herbaceous plants growing in Colchis. These are quite thermophilic species of relic plants, therefore they were preserved in places with a warm climate.
Examples of glacial relics are the marsh cinquefoil, growing in the Caucasus, and dwarf birch, preserved in central Europe.
Phylogenetic relics (living minerals)
These currently existing species belong to large taxa, almost completely extinct millions of years ago. They survived, as a rule, due to the isolation of their habitat from more progressive groups. Phylogenetic plants include relict plants such as ginkgo, metasequoia, horsetail, sciadopitis, vollemia, liquidambar, and velvichia.
Ginkgo
A relic tree, which is one of the oldest on Earth. Studies of fossil samples show that the age of the ginkgo is at least 200 million years. They appeared at the beginning of the Late Permian, and in the middle of the Jurassic at least 15 genera of Ginkgoae grew.
Ginkgo biloba (Ginkgo biloba ) is the only species that has survived to the present. This is a deciduous plant belonging to gymnosperms. Its height reaches 40 meters. Trees are characterized by a well-developed root system, resistant to adverse weather conditions, in particular to strong winds. There are specimens that have reached the age of 2.5 thousand years.
Since, in addition to ginkgo, pine and spruce belong to gymnosperms, the plant previously considered by us was also classified as coniferous, although it is very different from them. However, to date, there are suggestions that the ancestors of the Ginkgs are ancient seed ferns.
Previously, these so-called living minerals could only be seen in China and Japan. But today, the plant is cultivated in parks and botanical gardens in North America and the subtropical zone of Europe.
Metasequoia
Belongs to the genus of conifers of the Cypress family. Currently, it exists in the only surviving relict form - Metasequoia glyptostrobida (Metasequoia glyptostroboides). Plants of this species were widespread in forests in the Northern Hemisphere. They began to die out due to a change in climatic conditions and competition with broad-leaved species. Living specimens of this tree were discovered in 1943. Prior to this, metasequoia was found only in the form of fossils and was considered extinct.
To date, these relic plants in the wild have been preserved only in the provinces of Sichuan and Hubei (Central China) and are listed in the International Red Book, as they are on the verge of extinction.
Due to the external attractiveness, metasequoia is grown in gardens and parks of Central Asia, Ukraine, Crimea, the Caucasus, as well as in Canada, the USA and in several European countries.
Liquidambar
Liquidambar belongs to the genus of flowering plants of the Aptingian family, which includes five species. These relic plants were widely distributed in the Tertiary period. The reason for their extinction in Europe was large-scale icing during the ice age. Climate change has contributed to the extinction of the species from the territories of North America and the Far East.
Today liquidation bars are common in North America, Europe and Asia.
They are quite large deciduous trees, growing up to 25-40 meters, with palmate-lobed leaves and small flowers collected in a spherical inflorescence. The fruit has the appearance of a wooden box inside which there are many seeds.
Horsetail
These relics are plants of the vascular genus that have been preserved in large numbers and currently number about 30 species. All varieties currently growing are perennial herbs. In height, they can grow up to several meters. The largest species is the giant horsetail (Equisetum giganteum). With a trunk diameter not exceeding 0.03 m, its maximum height can reach 12 meters. Giant horsetail is growing in Chile, Mexico, Peru and Cuba. The most powerful species, Schaffner horsetail (Equisetum schaffneri), also grows there. At a height of 2 meters, its diameter reaches 10 cm.
Horsetail stems are characterized by high rigidity, which is explained by the presence of silica in them. Plants also have highly developed rhizomes with subordinate roots in the nodes, due to which they are very resistant to various adverse factors and can even survive a forest fire. Horsetails are widespread on most continents, with the exception of Australia and Antarctica.
Wolemia
Coniferous relict tree, represented by a single species - Wolemeia noble (Wollémia nóbilis). It is one of the oldest plants. It grew in the Jurassic period. The plant was considered extinct long ago. However, in 1994, the vollemia was discovered by one of the employees of the National Park of Australia, David Noble, in whose honor the species was named (nobilis - "noble"). Almost a whole relic grove was found. The oldest of the discovered trees is supposedly over 1000 years old.
Wolemia is a fairly tall tree. So, it can reach 35-40 meters. The foliage of the plant is completely identical to the leaves of Agatis jurassic, which grew about 150 million years ago and is the alleged fossil ancestor of vollemia from the late Jurassic period.
Sciadopitis
It exists in a single form - Sciadopitis whorled (Sciadopitys verticillata). In past geological eras, this genus of trees was very widespread. This is evidenced by the fact that their remains were found in Cretaceous deposits in Japan, Greenland, Norway, Yakutia, and in the Urals.
At present, under natural conditions, sciadopitis grows only on some islands in Japan, where it has survived at an altitude of 500-1000 m above sea level in humid mountain forests, as well as on slopes, in deep gorges, in groves.
Sciadopitis is an evergreen tree with a pyramidal crown. It can grow to a height of 40 m. The trunk size in girth is up to 4 meters. It is characterized by very slow growth. The tree is often called the "umbrella pine" because of the unique structure of the needles. Its flattened needles, having an average length of up to 0.15 m, form false whorls and are spread apart, like the needles of an umbrella.
The fruits of sciadopitis are oval cones, the ripening period of which is two years.
Since sciadopitis can grow in containers for a long time, it is often used in decorative horticulture as an indoor and greenhouse plant. As a park culture introduced in Europe since the 19th century.
Welvichia
The amazing Velvichia (Welwítschia mirábilis) is the only species that has survived to this day. One of the three representatives of the former quite numerous class of oppressive, which are found today. Own name Velvichia received amazing thanks to its unusual appearance.
The plant does not resemble grass, nor a bush, nor a tree. It is a thick trunk, 15-50 centimeters protruding above the surface of the soil. The rest of it is hiding underground. And while the relic leaves reach 2 m in width and 6 m in length. Some specimens are over 2000 years old.
The place of growth of Welwitschia is the southwestern part of Africa, namely, the rocky desert of Namib, located along the coast of the Atlantic Ocean. The plant is very rarely seen further than 100 m from the coast. This is because it is precisely such a distance that fogs can overcome, which for velvichy are a source of life-giving moisture.