Features of the introduction of representatives of the genus Inula L

Representatives of the genus Inula are promising for introduction due to their wide range of uses. So, many species are ornamental plants, promising for introduction, including in urban landscaping. Several species are medicinal plants, and even though recently the chemical composition of certain species of this genus has been studied, it was evident that this work must be continued to maximize the study of the possibilities of this genus. The article discusses the experience of introducing representatives of the genus Inula in the Main Botanical Garden named after N.V. Tsitsin RAS in the aspect of general introduction work both in the gardens of the former USSR, Western Europe, and the USA. The fact states that only natural species found in the natural flora of the USSR prevailed in the botanical gardens of the countries of the former USSR. At the same time, East Asian and Iranian-Turanian species are representatively represents in foreign botanical gardens. For the Russian flora and neighboring countries (within the borders of the former USSR), 33 species have been recorded, of which 15 species have undergone an introduction study at the Russian Academy Science (RAS). For all species studied at the GBS RAS, the flowering time in the conditions of central Russia was analyzed, the possibilities of using it both for decorative and other purposes were indicated. According to literary sources, the analysis of the component composition of raw materials of 16 natural species found within this region was carried out.


Introduction
The expansion of the cultural flora through the introduction of natural species into its composition is the main direction of the activity of botanical gardens. At the same time, an important task is to select the most promising plants with high decorative qualities, medicinal or technical properties. Such a valuable complex of characters characterizes representatives of the genus Inula L. The main purpose of this work is to summarize the results of the introduction of various species of this genus into the cultural flora.
Natural species of the genus Inula L. are interested not only as a source of medicinal raw materials but also as quite ornamental plants promising for introduction studies. According to various sources, the volume of this genus ranges from 90 (Coombes, 2009) to 100 natural species found in Asia, Africa, and Europe (Coombes, 2012). Particular attention in the article has apeared to the species of the genus Inula, found in the territory of the former USSR. The interest reason of scientists explained by the species diversity, and the introduction knowledge In the natural flora of Russia and neighboring states (within the former USSR), 33 species were recorded (Flora SSSR, 1959). Moreover, the geographical distribution of this genus is of particular interest. Thus, there are 3 separate centers with the maximum species diversity -the Caucasus, Central Asia and the Far East. In general, for Central Asia, the maximum species diversity is noted, so of the 16 species found here -10 species are characteristic only for this region, and of them -6 are endemic. Central Asian species are mountain plants, the introduction of which, especially endemic species, is difficult in the conditions of central Russia. Caucasian species of this genus are also interesting. Therefore, for the Caucasus flore, 13 species have been identified, of which 6 are mostly found only in this region. Ecologically, the group of Caucasian species is more diverse -in addition to mountain slopes, some species are also characteristic of meadow (alpine and subalpine), steppe and forest communities. Potentially, these species, except the Transcaucasian species, characterized by more xerophilic growing conditions, are promising for introduction in Central Russia. The Far Eastern group is represented by 3 species associated with forest and meadow communities.
Simultaneously, no purely European and Siberian species for this genus have been identified in the flora of the former USSR. 11 species characterized by a wide range. The main feature of such species is a wide reaction rate and prospects for introduction work. The most common are only two species -Inula salicina L. and Inula britannica L. are found in a wide strip covering Europe, Siberia (Western and Eastern), partly -Central Asia and the Far East.
As already noted above, when introducing plants, it is important not only to assess the resistance of a particular species to ecological and climatic conditions, but also to identify valuable economic qualities of plants -

Results and Discussions
The most common species in the cultivated flora is I. helenium L., a medicinal and ornamental plant introduced into cultivation in antiquity (Poletiko and Mishenkova, 1967). Also, five more species have been cultivated as ornamental for a long time -I. ensifolia L. The introduction study of representatives of the genus Inula in the Main Botanical Garden of the Russian Academy of Sciences accords to the standard two-stage technique, which includes the stage of the primary introduction study, after receiving the preliminary information about the prospects of introducing the studied samples into the culture, the second stage of the introduction studies is carried out. The genus Inula's collection fund is formed based on two methods: generic complexes and ecological-phytocenotic. In the Laboratory of Ornamental Plants of the MBG RAS, species of the genus Inula were collected and studied within the framework of generic complexes proposed by F.N. Rusanov (1950). A feature of this introduction method is the broadest possible attraction of both biological species and varieties that are grown at the identical exposition, which makes it possible to identify the most stable, highly decorative, and promising samples for introduction into the cultural flora of the region. Despite the apparent advantages, the Rusanov method also has some disadvantages. Thus, depending on the soil and climatic conditions of the point of introduction, this approach has several limitations, which often prevent the introduction of a significant number of representatives of a particular botanical taxon. Thus, it is not acceptable for genera in which species with different ecological preferences are represented. However, individual representatives of the genus Inula included in the modern collection fund do not require specific growing conditions, and in general, this method has shown its effectiveness in assessing the introduction prospects of this genus. The second method of introduction, used at MBG RAS in the Laboratory of Natural Flora, is ecological-phytocenotic (Trulevich, 1991). This methods based on the formation of collections of plants characterized by different taxonomic affiliations but having a common ecology -plants of forests, steppes, scree, etc. This method allows you to grow introduced plants in the most comfortable conditions for them.
In addition to these species, the following species of elecampane were introduced in the botanical gardens of the former USSR -I. germanica L., I. Grandiflora, I. macrophylla Kar. et Kir.
Among the species that have passed the introduction test at the GBS RAS, the most decorative and promising introduction into mass urban landscaping are the following species: -I. Magnifica, I. racemosa, I. royleana, I. Grandiflora. For compositions imitating natural communities, it is promising to use such species as I. helenium, I. Britannica, I. ensifolia. Almost all species, except for I. Mariae (a biological species from Transcaucasia, which characterized by a narrow reaction rate, did not bloom under the conditions of Moscow and was unstable in culture) are stable under cultural conditions, form seeds annually, in some cases mass selfseeding is possible (I. helenium, I. salicina).
When Group 3 -late-blooming (August-September) -I. japonica, I. racemosa, I. thapsoides. It should be noted that representatives of the third group are the most interesting for introduction into urban gardening due to the relatively late flowering period.
Among the species tested in the introduction experiment, representatives of meadow and subalpine communities predominate. Long-term introduction tests conclude that further introduction testing of new species from these communities may be promising. Rocky species are less resistant and require particular soil and climatic conditions; they are often not long-lived in culture.
As mentioned above, in addition to decorative properties, several elecampane species have other valuable qualities. Thus, Inula helenium possesses medicinal and nutritional valuable traits and the possibility of using it as natural insecticides and dyeing properties (Pashina and Kukhareva, 1986). Inula macrophylla -medicinal, technical, and melliferous plant; I. salicina has medicinal properties, and I. Aspera is a melliferous plant, which also has fodder value. Britannica -medicinal, fodder, and melliferous plant; I. hirta is a medicinal plant. Other types of elecampane also have medicinal properties: I. Conyza DC., I. germanica, I. ensifolia, I. Magnifica (Solodko et al., 2006).
The study of the chemical composition of representatives of the genus Inula has been carried out for a long time. However, it is in recent years that there has been an increase in interest in research on the study of biologically active substances of plant origin, including in representatives of the genus Inula  (Table 1).