Relics are organisms that have survived on Earth in certain areas since antiquity, despite changing living conditions. They are the remains of ancestral groups that were widespread in past geological epochs. The word "relic" comes from the Latin reliquus, which means "remaining" in translation.
Relic plants and animals are of great scientific value. They are carriers of information and can tell a lot about the natural environment of past eras. Let's get acquainted with plant organisms classified as relic.
Geographic relic plants
Geographic relic plants include species that have survived in a particular region as a remnant of past geological epochs, in which the conditions of existence differed significantly from modern ones. So, the Neogene (tertiary) relicts include forest-forming tree species (chestnut, zelkova, and some others), a number of evergreen shrubs (Colchian goatwort, boxwood, butcher's broom, Pontic rhododendron, etc.), as well as herbaceous plants growing in Colchis. This is enoughheat-loving types of relict plants, so they are preserved in places with a warm climate.
Examples of glacial relics are marsh cinquefoil, growing in the Caucasus, and dwarf birch, preserved in central Europe.
Phylogenetic relics (living fossils)
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 such relic plants as ginkgo, metasequoia, horsetail, sciadopitis, wollemia, liquidambar, velvichia.
Ginkgo
Relic tree, which is one of the most ancient on Earth. Studies of fossil specimens show that the age of Ginkgo is at least 200 million years old. They appeared at the beginning of the Late Permian, and in the middle of the Jura there were already at least 15 ginkgo genera.
Ginkgo biloba (Ginkgo biloba) – is the only species that has survived to this day. This is a deciduous plant belonging to the 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, pines and spruces belong to gymnosperms, the plant we were previously considering was also classified as coniferous, although itvery different from them. However, today there are suggestions that the ancient seed ferns are the ancestors of Ginkgoaceae.
Previously, these so-called living fossils could only be seen in China and Japan. But today the plant is cultivated in parks and botanical gardens in North America and subtropical Europe.
Metasequoia
Belongs to the genus of coniferous trees of the Cypress family. Currently, there is the only surviving relic species - Metasequoia glyptostroboides (Metasequoia glyptostroboides). Plants of this species were widely distributed 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, the metasequoia was found only in the form of fossils and was considered extinct.
Today, these relic plants in the wild have survived 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 its external attractiveness, metasequoia is grown in gardens and parks in Central Asia, Ukraine, the Crimea, the Caucasus, as well as in Canada, the USA and a number of European countries.
Liquidambar
Liquidambar (Liquidambar) belongs to the genus of flowering plants of the family Aptingiaceae, which includes five species. These relict plants were widespread in the Tertiary period. The reason for their extinction in the territoryEurope became a 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 liquidambars are widespread in North America, Europe and Asia.
They are rather large deciduous trees growing up to 25-40 meters, with palmate-lobed leaves and small flowers collected in a spherical inflorescence. The fruit looks like a woody box, inside which there are many seeds.
Horsetails
These relics are plants of the genus vascular, preserved in large numbers and numbering today about 30 species. All varieties now growing are perennial herbs. They can grow up to several meters in height. 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 grows in Chile, Mexico, Peru and Cuba. The most powerful species, Schaffner's horsetail (Equisetum schaffneri), also grows there. With a height of 2 meters, its diameter reaches 10 cm.
Horsetail stalks are characterized by high rigidity, which is explained by the presence of silica in them. Also, plants have highly developed rhizomes with adventitious roots at 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 ofare only Australia and Antarctica.
Wollemy
Coniferous relict tree, represented by a single species - Noble Wollemia (Wollémia nóbilis). It is one of the oldest plants. It grew in the Jurassic period. The plant was thought to be extinct. However, in 1994, Wollemia was discovered by one of the Australian National Park staff, David Noble, after whom the species was named (nobilis - "noble"). Almost a whole relic grove was found. The oldest tree discovered is said to be over 1,000 years old.
Wollemy 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 Wollemia from the late Jurassic period.
Sciadopitis
Exists in a single form - Sciadopitys whorled (Sciadopitys verticillata). In past geological epochs, this genus of trees had a huge distribution. This is evidenced by the fact that their remains were found in the Cretaceous deposits in Japan, Greenland, Norway, Yakutia, and the Urals.
At the moment, under natural conditions, siadopitis grows only on some islands in Japan, where it has been preserved at an altitude of 500-1000 m above sea level in humid mountain forests, as well as on slopes, in remote gorges, in groves.
Sciadopitis is an evergreen tree,having a pyramidal crown. It can grow up to 40 m in height. The size of the trunk in girth is up to 4 meters. Characterized by very slow growth. The tree is often referred to as "umbrella pine" due to the unique structure of its needles. Its flattened needles, having an average length of up to 0.15 m, form false whorls and are moved apart, like the spokes of an umbrella.
Sciadopitis fruits are oval-shaped cones, the ripening period of which is two years.
Because sciadopitis can grow in containers for a long time, it is often used in ornamental gardening as a houseplant and greenhouse plant. As a park culture introduced in Europe since the 19th century.
Velvichia
Welwitschia amazing (Welwítschia mirábilis) - the only species that has survived to this day. One of the three representatives of the former quite numerous oppressive class, which are still found today. Velvichia amazing got its name due to its unusual appearance.
The plant doesn't look like grass, bush or tree. It is a thick trunk, protruding 15-50 centimeters above the soil surface. The rest of it is hidden underground. And at the same time, the leaves of the relic reach 2 m in width and 6 m in length. Some specimens are over 2000 years old.
Welwitschia grows in the southwestern part of Africa, namely the rocky Namib Desert, located along the coast of the Atlantic Ocean. The plant is very rarely found further than 100 m from the shore. This isdue to the fact that it is this distance that fogs can overcome, which for Velvichia are a source of life-giving moisture.
