Boswellia
{{Short description|Genus of flowering plants}}
{{automatic taxobox
| image = Boswellia_sacra_-_Köhler–s_Medizinal-Pflanzen-022.jpg
| taxon = Boswellia
| authority = Roxb. ex Colebr.The genus Boswellia, and the type Boswellia serrata, were first described and published in Asiatic Researches 9: 379. 1807. {{cite web |url=http://www.tropicos.org/Name/40029741 |title=Name - Boswellia Roxb. ex Colebr. |quote=Type Specimens: T: Boswellia serrata Roxb. ex Colebr. |work=Tropicos |publisher=Missouri Botanical Garden |location=Saint Louis, Missouri |accessdate=November 24, 2012 |archive-url=https://web.archive.org/web/20170717183043/http://www.tropicos.org/Name/40029741 |archive-date=July 17, 2017 |url-status=dead }}
| subdivision_ranks = Species
| subdivision = see Text
|synonyms_ref =
- Libanotus {{au|Stackh. in De Liban: 13 (1814), nom. superfl.}}
- Libanus {{au|Colebr. in Asiat. Res. 9: 382 (1807), not validly publ.}}
- Ploesslia {{au|Endl. in S.L.Endlicher & E.Fenzl, Nov. Stirp. Dec.: 38 (1839)}}
}}
Boswellia is a genus of trees in the order Sapindales, known for its fragrant resin. The biblical incense frankincense is an extract from the resin of the tree Boswellia sacra, and is now produced also from B. frereana.{{cite journal |author=Tucker, A. |year=1986 |title=Frankincense and myrrh |journal=Economic Botany |volume=40 |issue=4 |pages=425–433 |doi=10.1007/bf02859654}} Boswellia species are moderate-sized flowering plants, including both trees and shrubs.
Description
Boswellia species are dioecious,Judd, W.S., Campbell, C.S., Kellogg, E.A., Stevens, P.F., and M.J. Donoghue. 2008. Plant Systematics: A Phylogenetic Approach 3rd ed. Sinauer Associates, Inc., Sunderland, Massachusetts. or hermaphroditic.{{cite journal|doi=10.1111/j.1756-1051.2008.00245.x|title=Ambilobea, a new genus from Madagascar, the position of Aucoumea, and comments on the tribal classification of the frankincense and myrrh family (Burseraceae)|year=2008|last1=Thulin|first1=Mats|last2=Beier|first2=Björn-Axel|last3=Razafimandimbison|first3=Sylvain G.|last4=Banks|first4=Hannah I.|journal=Nordic Journal of Botany|volume=26|issue=3–4|pages=218–229|url=http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-105850|doi-access=free}} The flowers may have four or five faintly connate but imbricate sepals with an equal number of distinct, imbricate petals. Also, the stamens, that may contain nectar discs, have distinct glabrous filaments that occur in one or two whorls and in numbers equaling or twice the number of petals; the tricolporate pollen is contained within two locules of the anthers that open longitudinally along slits. The gynoecium contains three to five connate carpels, one style, and one stigma that is head-like to lobed. Each locule of the superior ovary has two ovules with axile placentation that are anatropous to campylotropous. The one- to five-pitted fruit is a drupe that opens at maturity. The endosperm is usually lacking in the embryo.
Taxonomy
The genus name honors Scottish botanist John Boswell, 1710–1780 (incidentally, uncle of writer James Boswell).{{Cite book|url=https://books.google.com/books?id=A68qyOyhOdkC&q=boswell+species+names&pg=PA331|title = CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology|isbn = 9780849326738|last1 = Quattrocchi|first1 = Umberto|date = 1999| publisher=CRC Press }}
The genus was first published in Asiat. Res. 9 on page 379 in 1807.
Species
As accepted by Plants of the World Online;{{cite web |title=Boswellia Roxb. ex Colebr. {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:5117-1 |website=Plants of the World Online |access-date=16 November 2023 |language=en}}
{{div col|colwidth=20em}}
- B. ameero Balf.f.
- B. asplenifolia {{au|(Balf.f.) Thulin}}
- B. bullata Thulin
- B. dalzielii Hutch.
- B. dioscoridis Thulin
- B. elongata Balf.f.
- B. frereana Birdw.
- B. globosa Thulin
- B. microphylla Chiov.
- B. nana Hepper
- B. neglecta S.Moore
- B. occulta {{au|Thulin, DeCarlo & S.P.Johnson}}
- B. ogadensis Vollesen
- B. ovalifoliolata N.P.Balakr. & A.N.Henry
- B. papyrifera (Del.) Hochst.
- B. pirottae Chiov.
- B. popoviana Hepper
- B. rivae Engl.
- B. ruspoliana Engl.
- B. sacra Flueck.
- B. serrata Roxb. ex Colebr. (type)
- B. socotrana Balf.f.
{{div col end}}
World Flora Online only accepts 20 species; B. ameero, B. bullata, B. carteri {{au|Birdw.}}, B. dalzielii, B. dioscoridis, B. elongata, B. frereana, B. globosa, B. microphylla, B. nana, B. neglecta, B. ogadensis, B. ovalifoliolata, B. papyrifera, B. pirottae, B. popoviana, B. rivae, B. sacra, B. serrata and B. socotrana.{{cite web |title=Boswellia Roxb. |url=https://www.worldfloraonline.org/taxon/wfo-4000005070 |website=worldfloraonline.org |access-date=16 November 2023}}
Distribution
The genus is native to tropical regions of Africa and Asia. The distributions of the species are primarily associated with the tropics.Weeks, A., Daly, D.C. and B.B. Simpson. 2005. "The phylogenetic history and biogeography of the frankincense and myrrh family (Burseraceae) based on nuclear and chloroplast sequence data". Molecular Phylogenetics and Evolution, 35: 85–101.
The greatest diversity of species presently is in Africa and India.
They are native to the countries (and regions) of Benin, Burkina, Cameroon, Central African Republic, Chad, Eritrea, Ethiopia, Ghana, India, Ivory Coast, Kenya, Mali, Niger, Nigeria, Oman, Senegal, (island of) Socotra, Somalia, Sudan, Tanzania, Togo, Uganda, West Himalaya and Yemen.
Ecological status
In 1998, the International Union for Conservation of Nature (IUCN) warned that one of the primary frankincense species, Boswellia sacra, is "near threatened". Frankincense trees are not covered by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, but experts argue that Boswellia species meet the criteria for protection. In a 2006 study, an ecologist at Wageningen University & Research claimed that, by the late-1990s, Boswellia papyrifera trees in Eritrea were becoming hard to find. In 2019, a new paper predicted a 50% reduction in Boswellia papyrifera within the next two decades. This species, found mainly in Ethiopia, Eritrea, and Sudan, accounts for about two-thirds of global frankincense production. The paper warns that all Boswellia species are threatened by habitat loss and overexploitation. Most Boswellia grow in harsh, arid regions beset by poverty and conflict. Harvesting and selling the tree's resin is one of the only sources of income for the inhabitants, resulting in overtapping.{{cite news |last1=Fobar |first1=Rachel |title=Frankincense trees—of biblical lore—are being tapped out for essential oils |url=https://www.nationalgeographic.com/animals/2019/12/frankincense-trees-declining-overtapping/ |archive-url=https://web.archive.org/web/20191213163409/https://www.nationalgeographic.com/animals/2019/12/frankincense-trees-declining-overtapping/ |url-status=dead |archive-date=December 13, 2019 |accessdate=16 December 2019 |work=National Geographic |date=13 December 2019}}
Frankincense
{{main|Frankincense}}
The four main species of Boswellia, B. sacra (synonyms B. carteri and B. bhaw-dajiana), B. frereana, B. papyrifera, and B. serrata, produce true frankincense, and each type of resin is available in various grades. The grades depend on the time of harvesting, and the resin is hand sorted for quality.
References
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