View source for Prunus africana

{{Taxobox
| color = lightgreen
| name = Red Stinkwood
| image = Prunus_sappling.jpg
| image_width = 250px
| status = VU
| status_system = iucn3.1
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Magnoliopsida]]
| ordo = [[Rosales]]
| familia = [[Rosaceae]]
| subfamilia = [[Prunoideae]]
| genus = ''[[Prunus]]''
| species = '''''P. africana'''''
| binomial = ''Prunus africana''
| binomial_authority = ([[Joseph Dalton Hooker|Hook f.]]) [[Cornelis Kalkman|Kalkman]]
}}

'''''Prunus africana''''' (Syn. ''Pygeum africanum'' [[Joseph Dalton Hooker|Hook. f.]]; '''Pygeum, Iron Wood, (Red) Stinkwood, African Plum, African Prune, African Cherry, Bitter Almond'''; [[Amharic]] tikur inchet; [[Chagga]] Mkonde-konde; [[Kikuyu]] Muiri; [[Luganda]] Ntasesa; [[Xhosa]] uMkakase; [[Zulu]] Inyazangoma-elimnyama; [[Afrikaans]] Rooistinkhout) is an evergreen [[tree]] native to the [[montane]] regions of [[Sub-Saharan Africa]] and the Islands of [[Madagascar]], [[Sao Tome]], [[Fernando Po]] and [[Grand Comore]] at about 900-3400 m. of altitude. The mature tree is 10-25 m. high, open-branched and often pendulous in forest, shorter and with a round crown of 10-20 m. diameter in grassland. It requires a moist climate, 900-3400 mm annual rainfall, and is moderately frost-tolerant.<ref name=prunafr>{{cite web | title=Prunus africana (Hook. f.) Kalkman |  work=Germplasm Resources Information Network (GRIN) Taxonomy for Plants | author=U. S. Department of Agriculture (USDA) | url=http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?29828 | format=html }} </ref><ref name=pygafr>{{cite web | title=Pygeum africanum Hook. f. |  work=Germplasm Resources Information Network (GRIN) Taxonomy for Plants | author=U. S. Department of Agriculture (USDA) | url=http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?30392 | format=html }} </ref><ref>{{cite book | first=Najma | last=Dharani | title=Field Guide to Common Trees and Shrubs of East Africa | publisher=New Holland | date=2002 | id-ISBN 1868726401 | pages=page 150}} Previewable Google Books. </ref><ref name=sustain>{{cite web | last=Cunningham | first=A.B. | coauthors=Mbenkum, F.T. | title=Sustainability of harvesting Prunus africana bark in Cameroon: A medicinal plant in international trade | work=People and Plants working papers | publisher=Division of Ecological Sciences, UNESCO | date=May 1993 | url=http://peopleandplants.org/whatweproduce/Workingpapers/pdf/wp2.pdf | format=pdf }}</ref><ref name=who>{{ cite book | author=World Health Organization, Inc. NetLibrary | title=WHO Monographs on Selected Medicinal Plants: Volume 2 | publisher=World Health Organization | date=2002 | location=Geneva | id=ISBN 9241545372 | pages=page 246 }} Previewable Google Books.</ref><ref>{{cite web | last=Nonjinge | first=Siyabulela | title=Prunus africana (Hook. f.) Kalkman | work=PlantZAfrica.com | publisher=South African National Biodiversity Institute | date=October 2006 | url=http://www.plantzafrica.com/plantnop/prunusafri.htm | format=html }}</ref>

The bark is black to brown, corrugated or fissured and scaly, fissuring in a characteristic rectangular pattern. The [[leaf|leaves]] are alternate, simple, long (8-20 cm.), elliptic, bluntly or acutely pointed, [[glabrous]] and dark green above, pale green below, with mildly serrate margins. A central vein is depressed on top, prominant on the bottom. The 2-cm [[Petiole (botany)|petiole]] is pink or red. The [[flower]]s are androgynous, 10-20 [[stamen]]s, insect-pollinated, 3-8 cm., greenish white or buff, and are distributed in 70-mm [[axillary]] [[raceme]]s. The plant flowers October through May. The [[fruit]] is red to brown, 7-13 mm., wider than long, two-lobed with a seed in each lobe. It grows in bunches ripening September through November, several months after pollination.

==Ecology==
[[Image:Prunus_africana_nectaries.jpg|thumb|left|Extrafloral nectaries along the leaf margin.]]
As with other members of the [[Prunus]] genus, ''Prunus africana'' possesses extrafloral nectaries to provide anti-herbivore insects with a nutrient source in return for protecting the foliage.

The fruit is too bitter to be of interest to man; however, it is a favored food supply for many animals, who spread the seeds. [[Dian Fossey]] reports of the [[Mountain Gorilla]]:<ref>{{cite book | first=Dian | last=Fossey | authorlink=Dian Fossey | title=Gorillas in the Mist | publisher=Houghton Mifflin Books | date=2000 | id=ISBN 061808360X | pages=page 146 }}</ref> "The northwestern slopes of [[Visoke]] offered several ridges of Pygeum africanum .... The fruits of this tree are highly favored by gorillas." ''East African Mammals'' reports that stands of Pygeum are the habitat of the rare [[Carruther's Mountain Squirrel]] and asserts that "This forest type tends to have a rather broken canopy with many trees smothered in climbers and dense tangles of undergrowth."<ref>{{cite book | first=Jonathan | last=Kingdon | title=East African Mammals: an Atlas of Evolution in Africa: Volume IIB | publisher=University of Chicago Press | place=Chicago | date=1984 | pages=page 389 | id=ISBN 0226437183 }}</ref>

==Uses==
[[Image:Prunus africana MS 3588.jpg|thumb|left|Prunus africana with stripped bark.]]
[[Pygeum]], an herbal remedy for [[benign prostatic hyperplasia]] (BPH), is prepared from the bark of Prunus africana. The collection of mature bark for this purpose has resulted in the species becoming endangered, due to some harvesters (spurred on by the high price per Kilo of Bark) removing too much of the bark in an unsustainable manner. In the 1990s it was estimated that 35,000 debarked trees were being processed annually. The growing demand for the bark has led to the cultivation of the tree for its medicinal uses.<ref name=sustain/>

The timber is a hardwood employed in the manufacture of axe and hoe handles, utensils, wagons, floors and furniture. The wood is tough, heavy, straight-grained and pink, with a pungent bitter-almond smell when first cut, turning mahogony and odorless later.<ref name=who/> It finds use also as firewood.

==Discovery and classification==
The name of the remedy, [[Pygeum]], comes from the name of the plant, which was discovered to botany by [[Gustav Mann]] during his now famous first European exploration of the [[Cameroon line|Cameroon Range]], with [[Richard Francis Burton]] and [[Alfred Saker]], in 1861. A letter from Mann to the [[Linnean Society of London]], read by [[William Jackson Hooker]], then Director of the [[Royal Botanic Gardens, Kew]], on June 5, 1862, describes the naming of the peaks of the Cameroon Range (such as Mount Victoria, later Mount Cameroon<ref>The British names did not survive the transfer of Cameroon to Germany in 1884 and now are nearly unknown.</ref>) and the collection of specimens there.<ref>{{cite journal | last=Hooker | first=Sir W.J. | authorlink=William Jackson Hooker | title=Letter from Mr. G. Mann, Government Botanist, describing his Expedition to the Cameroon Mountains | journal=Journal of the Proceedings of the Linnean Society: Botany | volume=VII | pages=pages 1-13 | date=1864 | url=http://www.botanicus.org/page/166680}}</ref> The latter were shipped back to Kew for classification, which was duly performed by Hooker and his son, [[Joseph Dalton Hooker]], who had the responsibility of publishing them, as William died in 1865.

When the publication came out<ref>{{cite journal | last=Hooker | first=J.D. | authorlink=Joseph Dalton Hooker | title=On the Plants of the Temperate Regions of the Cameroons Mountains and Islands in the Bight of Benin; collected by Mr. Gustav Mann, Government Botanist | journal=Journal of the Proceedings of the Linnean Society: Botany | volume=VII | pages=pages 191-192 | date=1864 | url=http://www.botanicus.org/page/166680 }} The article occupies pages 171-240. The botanical abbreviation for this publication is J. Proc. Linn. Soc., Bot.</ref> the Hookers had named the plant Pygeum africanum, followed by the designation "n. sp.", an abbreviation for ''nova species''. The habitat is listed as "Cameroons Mountains, alt. 7000-7500 feet", which was above the tropical forest and in the alpine grasslands. Hooker notes that another specimen had been "gathered in tropical Eastern Africa" at 3000 feet by Dr. Kirk on an expedition of [[David Livingstone]].

The first publication of the synonym in 1864 had been preceded by publication of the bare name in 1863 in a book by [[Richard Francis Burton]].<ref>{{Citation | first=J.D. | last=Hooker | author-link=Joseph Dalton Hooker | contribution=Enumeration of the Mountain Flowering Plants and Ferns Collected by M. Gustav Mann, Government Botanist, during his various ascents of the Cameroons Mountains, of Clarence Peak, Fernando Po, and of the Peak of San thomé | title=Abeokuta and the Camaroons Mountains: An Exploration: Appendix III | year=1863 | pages=270-277 | place=London | publisher=Tonsley Brothers }}</ref> Evidently Hooker had already made the contents of J. Proc. Linn. Soc., Bot. 7 for 1864 available to some, as Burton mentions the volume and Mann's letter in 1863.<ref>Page 47, first note.</ref>

Hooker gives scant hint of why he chose Pygeum; however, what he does say indicates it was common knowledge among botanists. Kirk's specimen fruit was "a much depressed sphere." By this he undoubtedly meant to reference [[Joseph Gaertner]]'s genus of Pygeum, ''Pygeum'' Gaertn.<ref>{{cite web | title=Pygeum Gaertn. |  work=Germplasm Resources Information Network (GRIN) Taxonomy for Plants | author=U. S. Department of Agriculture (USDA) | url=http://www.ars-grin.gov/cgi-bin/npgs/html/genus.pl?16198 | format=html }} </ref>, which innovates Pygeum<ref>See under [[De Fructibus et Seminibus Plantarum]]. The edition is the 1788.</ref> from a Greek word, πυγή, "rump, buttock", because the two lobes of the fruit resemble the human [[gluteus maximus]] muscles.<ref>{{cite book | first=Umberto | last=Quattrocchi | title=CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms: Volume III M-Q | publisher=CRC Press | date=2000 | id=ISBN 0849326737}} Previewable Google Books.</ref>

In 1965 [[Cornelis Kalkman]] moved ''Pygeum'' to ''Prunus'' and this classification has the authority for now.<ref>{{cite journal | first=Cornelis | last=Kalkman | authorlink=Cornelis Kalkman | title=The Old World Species of ''Prunus'' subg. Laurocerasus including those formerly referred to as Pygeum | journal=Blumea | volume=13 | pages=1-115 }} The specification is Blumea 13:33.</ref> However, a recent cladistic study notes of ''Pygeum'': "its relationships to Prunus remain to be tested by molecular cladistics."<ref>{{cite journal | last=Bortiri | first=Esteban | coauthors=Oh, Sang-Hun; Gao, Fang-You; Potter, Dan | title=The Phylogenetic Utility Of Nucleotide Sequences Of SORBITOL 6-PHOSPHATE DEHYDROGENASE In Prunus (Rosaceae) | journal=American Journal of Botany | volume=89 | issue=11 | pages=1697–1708 | date=2002 | url=http://www.amjbot.org/cgi/reprint/89/10/1697.pdf }}</ref>

==Palaeobotanic evidence==
A 1994/1995 study published in 1997 by Marchant and Taylor did a pollen analysis on and [[Radiocarbon dating|radiocarbon dated]] two core samples from montane Mubindi Swamp in [[Uganda]].<ref>{{cite journal | first=Robert | last=Marchant | coauthors=Taylor, David | title=Late Pleistocene and Holocene History at Mubwindi Swamp, Southwest Uganda | journal=Quaternary Research | volume=47 | pages=316–328 | date=1997 | url=http://www.york.ac.uk/res/kite/people/marchant/RAM%20PDFs/QR%201997.pdf }}</ref> The swamp is a catchment at 2100 m. altitude between mountain ridges. It is a "moist lower montane forest" in [[Bwindi Impenetrable National Park|Bwindi Forest National Park]]. The investigators found that montane Prunus, represented by currently growing Prunus africana, has been in the catchment continuously since their Pollen Zone MB6.1, dated approximately 43000-33000 ybp.

==References==
{{Wikispecies|Prunus africana}}
{{Wikispecies|Cornelis Kalkman}}
{{Commons|Prunus africana}}
{{reflist}}

==Bibliography==
* {{cite book | first=J.B. |last=Hall | coauthors=Sinclair, Fergus L; O'Brien, Eileen M. | title=Prunus Africana - A Monograph | date=2000 | publisher=University of Wales | location=Bangor | id=ISBN 1842200488}}

==External links==
* {{cite web | author=Dailey, Bryan W. | coauthors=Fernandes, Erick C.M | title=The Effect of Ecological Conditions on Density and Growth of Prunus africana Seedlings in Madagascar | publisher=Cornell University | url= http://www.css.cornell.edu/research/prunus/ | format=html}}
* {{cite web | title=Prunus africana | format=pdf | url=http://www.wwf.org.uk/filelibrary/pdf/pafricana.pdf | author=WWF }}



 




[[Category:Rosaceae]]
[[Category:Flora of Madagascar]]
[[Category:Flora of South Africa]]
[[Category:Trees of Africa]]
[[Category:Medicinal plants]]