Dracaena ( lat. Dracāena ) - genus of plants of the Asparagaceae family, trees or succulent shrubs. Includes over one hundred species. most common in tropical and subtropical regions of the Old World [2] . Some species from ancient times are used as a source of the so-called " draconic blood " . Some species are cultivated as greenhouse and indoor plants. .
Dracaena | |||||||||||||||||||||
Dragon tree ( Dracaena draco ). Palma Island, Canary Islands | |||||||||||||||||||||
Scientific classification | |||||||||||||||||||||
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International Scientific Name | |||||||||||||||||||||
Dracaena Vand. ex L. (1767) | |||||||||||||||||||||
Typical view | |||||||||||||||||||||
Dracaena draco ( L. ) L. - Dragon Tree | |||||||||||||||||||||
Earlier this genus (as well as the genera Cordilina and Yucca ) was included in the Agave family ( Agavaceae ), later the genus was separated into an independent family Dracaenaceae ( Dracaenaceae ). Sometimes the genus was included in the family Iglitse ( Ruscaceae ). The APG III classification includes all these genera in the Asparagaceae family ( Asparagaceae ) .
Title
The scientific name of the genus , Dracaena , translated as "female dragon." In modern literature, the word “Dracaena” [3] is used as the Russian name of the genus; earlier (for example, in the Encyclopedic Dictionary of Brockhaus and Efron ) the genus was called “dragonberry” [4] . Vladimir Dahl in his " Explanatory Dictionary " as the naming of the genus Dracaena is given the word "dragon" [5] .
Spread
A large number of species of dracaena are found in Africa - both on the continent and on the surrounding islands, including Macaronesia , Madagascar and Mascarene Islands . Many species of this genus grow in South and Southeast Asia . The northern border of the African part of the range of the genus passes through Madeira , Ethiopia and Socotra , the northern border of the Asian part of the range - through the southern slopes of the eastern Himalayas , South China's Yunnan Province and the island of Taiwan . Several species of dracaena are found in New Guinea , as well as in the northeast Australian state of Queensland . There are only a few American species of dracaena; they are found in Brazil , Cuba , Central America (in Costa Rica and north), and also in Mexico [2] .
Biological description
The tree form of the genus is due to the secondary growth (thickening) of the stem. This growth is not due to the cambium activity (as in gymnosperms and dicots ), but as a result of the activity of meristematic cells that are located on the periphery of the stem [6] (similar character of thickening is also characteristic of other representatives of the Asparagus family, as well as for Aspodelia family ).
Outwardly, dracaenas look like members of the Cordyline genus ( Cordyline ), but dracaenes, unlike Cordilins , have a thickening of the underground part, never stolons develop, and the roots and rhizomes on the cut have an orange color (they are white on the cut) [7] . In addition, representatives of these genera differ in the number of ovules in the ovary .
The leaves are collected at the ends of the branches in bundles (the so-called "apical rosettes") [6] .
The perianth is simple , up to 4.5 cm long [2] , consists of six leaflets [8] - in most species of white or pink. Their lower part is usually up to one-third connected into a tube [2] . There are six stamens , with intrarush anthers , which are attached to the stamen filament by the backs and opened by longitudinal slits [8] . The flowers usually open at night, have a pleasant smell and produce a relatively large amount of nectar , attracting various insects - pollinators - mainly moths . The dracaena fragrant ( Dracaena fragrans ) is distinguished by a particularly pleasant smell, resembling the smell of honey or fresh hay [2] .
Anatropic ovules [8] . There are only one ovule in each nest of the three-pelvic ovary (and, accordingly, only one seed develops) - this is a fundamental difference between the dragon species and the representatives of the genus Cordyline , similar to the dragon seed, in which the number of ovules is not less than two [9] .
Use
Some species of dracaena emit a tarry juice of blood-red color, the so-called " dragon's blood " [2] . Since ancient times, it has been used in dried form in the Mediterranean countries for medicinal purposes, and also as a dye; in India, it was used in religious ceremonies [10] . The existence of a tree that grows on the island of Socotra and from which dragon blood can be obtained (the modern scientific name of this plant is Dracaena cinnabari ) was already known to Dioscorida in the 1st century of our era [2] .
The dragon's blood from both the Canarian dragon tree ( Dracaena draco ) and the dragon tree of Socotra ( Dracaena cinnabari ) is traditionally produced by the tapping method [11] . It is odorless, tasteless, soluble in acetic acid and other organic solvents . Its melting point is 70 ° C , at 210 ° C it begins to decompose. Used to obtain varnish for metal surfaces [11] [12] , in traditional medicine , as well as to tint wines; in the Canary Islands in prehistoric times, it was allegedly used for embalming [11] ; contains pigments of draco-carmine and [11] . In China , “dragon's blood” usually means a resin extracted from Dracaena cochinchinensis ; in traditional Chinese medicine, it is used to improve blood circulation in the treatment of various injuries, as well as in cases of stagnation and various pains [13] .
Cultivation
Many species of dracaena were introduced into culture as ornamental plants [14] (first of all, as ornamental deciduous). Among zelenolistnyh distinguish cultivated species (e.g., Dracaena aletriformis , Dracaena arborea , Dracaena concinna , Dracaena draco , Dracaena phrynioides , Dracaena reflexa , Dracaena thalioides ) and variegated (e.g., Dracaena fragrans , Dracaena goldieana , Dracaena sanderiana ) [7] . They are grown in open ground, in greenhouses , as well as indoor plants [15] [7] . Experiments conducted in the 1980s by NASA scientists with fragrant dracaena ( Dracaena fragrans ) showed that plants of this species are able to effectively remove harmful substances such as benzene , trichlorethylene and formaldehyde from the air of an enclosed space [16] .
In indoor gardening, dracaena is referred to as so-called “false palm trees” - plants with a relatively bare trunk, in the upper part of which is a rather lush crown of long leaves [15] . The "false palms" also include the genus Cordyline ( Cordyline ), whose representatives are often confused with dragon plants. .
Most of the cultivated species originate from tropical Africa , as well as from the Mascarene Islands ; They began to cultivate in the XIX century. One of the most common species in the culture of dracaena is Dracaena fragrant ( Dracaena fragrans ), originating from tropical Africa [14] . Among other popular cultural forms - Dracaena Godsefa (. Dracaena surculosa, syn Dracaena godseffiana ), Dracaena zakrivlonnaya (Dracaena reflexa), Dracaena zontikonosnaya ( Dracaena Umbraculifera ), Dracaena elegant ( Dracaena concinna ), Dracaena Hooker (Dracaena aletriformis, syn Dracaena hookeriana. ) [17] . In some species, the leaves may be variegated - for example, Sander dracaena ( Dracaena sanderiana ), fragrant dracaena ( Dracaena fragrans ) (variety 'Massangeana' ); Dracaena marginata leaves have drapes edged in red [15] .
Cultivation of dratsen in open ground is possible only in a subtropical or moderately warm climate - areas belonging to frost resistance zones from the 9th or 10th to the 11th or 12th (depending on the species). One of the most cold-resistant species is Dracaena Hooker ( Dracaena aletriformis ), which can withstand a drop in temperature to minus 7 ° C [15] . For normal development of plants in open ground requires abundant sunlight and well-drained soil. Dracaena bordered ( Dracaena marginata ) [15] can grow well in a thin shadow.
Taxonomy and classification
The first valid description of this genus of plants was published by Carl Linnaeus in October 1767 simultaneously in the work of Mantissa Plantarum and in the second volume of the 12th edition of The System of Nature , while in the Mantissa Plantarum Linnaeus pointed out the Italian scientist to the name of the taxon and his description Domenico Vandelli [18] .
According to the Germplasm Resources Information Network (2018), the Dracaena genus belongs to the Nolinoideae subfamily of the Asparagaceae family ( Asparagaceae ) [19] . For many years, the systematic position of this genus was extremely unstable: it was considered as part of the Agave ( Agavaceae ), Iglitse ( Ruscaceae ), Lily of the Valley ( Convallariaceae ), Lily ( Liliaceae ) families — or separated into its own Dracene ( Dracaenaceae ) family [3] [ 19] .
Types
Species of this genus can be divided into two groups based on their growth habits: a group of tree-sized varieties with strong trunks and hard, all-encompassing leaves, growing in arid semi-desert areas, and known as the Drakonovo Tree. A group of smaller, shrubby varieties with slender stems and flexible, belt-shaped leaves, growing like undergrowth in tropical forests (and very popular as houseplants), and known all together as shrub drapes.
According to the information of The Plant List (2013), the genus includes 113 species [20] . Some of them:
- Dracaena aletriformis ( Haw. ) Bos - Dracaena Hooker , or Dracaena Hooker , view from subtropical rain forests of South Africa [17]
- Dracaena arborea ( Willd. ) Link - Dracaena treelike
- Dracaena braunii Engl. - Dracaena Sander
- Dracaena cambodiana Pierre ex Gagnep. - Dracena of Cambodia , one of the sources of " draconic blood " [11]
- Dracaena cinnabari Balf.f. - Dracaena is cinnabaro-red , one of the sources of " draconic blood " [11]
- Dracaena cochinchinensis ( Lour. ) SCChen - the Cochinha dracaena , one of the sources of " draconic blood "
- Dracaena concinna - Dracaena smart , view from Mauritius and Madagascar [17]
- Dracaena draco ( L. ) L. typus [21] - Draconic tree , or Dracaena draconic , one of the sources of " draconic blood " [11]
- Dracaena fragrans ( L. ) Ker Gawl. - Dracaena fragrant
- Dracaena goldieana W.Bull ex Mast. & Moore - Dracaena Golden
- Dracaena ombet Heuglin ex Kotschy & Peyr. - Dracaena ombet , or Nubian dragon tree
- Dracaena reflexa Lam. - Dracaena turned off , or Dracaena crooked , view from Mauritius and Madagascar [17]
- Dracaena surculosa Lindl. - Dracaena is conforming , or Drazena Godsef
- Dracaena umbraculifera Jacq. - Dracaena umbrella-shaped , species found in Mauritius and Madagascar; distinguished by large flowers [17]
In addition, the genus includes a view from Burma and Thailand Dracaena kaweesakii Wilkin & Suksathan , described in 2013 [22] ; In 2014, the taxon entered the list of ten most remarkable species according to the International Institute for Species Research.
Notes
- ↑ On the conditionality of specifying the class of monocotyledons as a higher taxon for the group of plants described in this article, see the “APG Systems” section of the article “Monocotyledons” .
- ↑ 1 2 3 4 5 6 7 Ivanina, 1982 , p. 173.
- ↑ 1 2 Ivanina, 1982 .
- ↑ Beketov, A. N. Lileinye // Encyclopedic Dictionary of Brockhaus and Efron : in 86 tons (82 tons and 4 extras). - SPb. , 1890-1907.
- ↑ Dragon // Explanatory Dictionary of the Living Great Russian Language : in 4 t. / Ed.-comp. V.I. Dahl . - 2nd ed. - SPb. : M.O. Wolf Typography, 1880–1882.
- ↑ 1 2 Ivanina, 1982 , p. 169.
- ↑ 1 2 3 Saakov, 1985 , p. 92
- ↑ 1 2 3 Ivanina, 1982 , p. 170
- ↑ Ivanina, 1982 , p. 171.
- ↑ Belousova L. S., Denisova L. V. Rare plants of the world. - M .: Forest industry, 1983. - p. 152. - 344 p. - 20 000 copies
- ↑ 1 2 3 4 5 6 7 Ivanina, 1982 , p. 174.
- ↑ Dracon's blood // Debtor - Eucalyptus. - M .: The Soviet Encyclopedia, 1972. - (The Great Soviet Encyclopedia : [in 30 t.] / Ch. Ed. AM Prokhorov ; 1969-1978, vol. 8).
- ↑Fan J.-Y. et al . A Systematic Review of the Botanical, Phytochemical and Pharmacological Profile of Dracaena cochinchinensis , a Plant Source of the Ethnomedicine “Dragon's Blood” : [ eng ] : [ arch. September 27, 2015 ] // Molecules: Journal. - Basel , 2014. - № 19 (7). - p. 10650-10669. - ISSN 1420-3049 . - DOI : 10.3390 / molecules190710650 .
- ↑ 1 2 Ivanina, 1982 , p. 174-175.
- ↑ 1 2 3 4 5 Grigoriev (ed.), 2006 .
- ↑ Van der Neuer J. All about indoor plants that clean the air = All about air-Cleaning Houseplants. - Vilnius: Bestiary, 2012. - p. 31, 34, 48. - 80 p. - (Everything about…). - 5000 copies - ISBN 978-609-456-102-3 .
- ↑ 1 2 3 4 5 Ivanina, 1982 , p. 175.
- ↑ Dracaenaceae Dracaena Vand. : [ arch. 10.23.2018 ]: [ eng ] . - International Plant Names Index . - Date of appeal: 10/23/2018.
- ↑ 1 2 Dracaena Vand. : [ arch. 10.22.2018 ]: [ eng ] // Germplasm Resources Information Network (GRIN-Taxonomy) / National Germplasm Resources Laboratory. - Beltsville, Maryland: USDA , Agricultural Research Service, National Plant Germplasm System. - Date of appeal: 10/22/2018.
- ↑ Dracaena : [ arch. 04.09.2017 ]: [ eng ] . - The Plant List . Version 1.1., 2013. - Appeal Date: June 10, 2018.
- ↑ Dracaena D. Vandelli in Linnaeus, Mant. 9. 15-31 Oct 1767; Syst. Nat. ed. 12. 2: 229, 246. 15-31 Oct 1767 : [ arch. 04.06.2018 ]: [ eng ] // Index Nominum Genericorum. - The International Association for Plant Taxonomy (IAPT) . - Date of appeal: 04/06/2018.
- ↑ Wilkin et al., 2013 .
Literature
- Dracaena // Brockhaus and Efron Encyclopedic Dictionary : 86 tons (82 tons and 4 extra). - SPb. , 1890-1907.
- Ivanina L. I. The Dracena family (Dracaenaceae) // Plant Life : in 6 t. / Ch. ed. A.L. Tahtajan . - M .: Enlightenment , 1982. - V. 6: Flowering plants / ed. A.L. Tahtajyan. - p. 169-177. - 543 s. - 300 000 copies
- Saakov S. G. Rod Dracaena Vand. ex L. - Dracaena // Greenhouse and indoor plants and their care / resp. ed. R.V. Kamelin . - L .: Science, 1985. - pp. 92-94. - 621 s. - 45 000 copies
- Waterhouse, JT The Phylogenetic Significance of Dracaena- type growth. // Proc. Linn. Soc. NSW - 1987. - Vol. 109. - P. 129-128.
- Wilkin P., Suksathan P., Keeratikiat K., van Welzen P., Wiland-Szymanska J. A new species from Thailand and Burma, Dracaena kaweesakii Wilkin & Suksathan (Asparagaceae subfamily Nolinoideae) : [ eng ] : [ arch. September 5, 2018 ] // PhytoKeys: Journal. - 2013. - Vol. 26 (2 October). - P. 101-112. - ISSN 1314-2003 . - DOI : 10.3897 / phytokeys.26.5335 .
Links
- Socotra botany . Royal Botanic Garden, Edinburgh.
- Dracaeni diseases