Sclerocarya birrea

{{Speciesbox

|name = Marula

|image = Marula02.jpg

|image2 = Kruger Park Scenery - HDR (7645852578).jpg

|image2_caption = S. birrea with and without foliage

|status = LC

|status_system = IUCN3.1

|status_ref = {{cite iucn |author1=IUCN SSC Global Tree Specialist Group & Botanic Gardens Conservation International (BGCI) |year=2024 |title=Sclerocarya birrea |volume=2024 |page=e.T208166817A208357864 |access-date=27 July 2024}}

|genus = Sclerocarya

|species = birrea

|authority = (A.Rich.) Hochst.

|subdivision_ranks = Subspecies

|subdivision =

Sclerocarya birrea subsp. afra {{small|(Sond.) Kokwaro}}
Sclerocarya birrea subsp. birrea
Sclerocarya birrea subsp. multifoliolata {{small|(Engl.) Kokwaro}}

|subdivision_ref = {{cite web |title=Sclerocarya birrea (A.Rich.) Hochst. |url=https://powo.science.kew.org/taxon/urn%3Alsid%3Aipni.org%3Anames%3A71162-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=27 July 2024}}

|synonyms =

Spondias birrea A. Rich.
Poupartia birrea (A. Rich.) Aubrév.

|synonyms_ref =

|}}

File:Marula04.jpg

File:Marula Baum Blüte in Swaziland.jpg

File:Marula01.jpg

File:Sclerocarya birrea subsp caffra, saailing, Skrikfontein, a.jpg emarginate leaflets with toothed margins, features not present in adult plants]]

Sclerocarya birrea ({{langx|grc|σκληρός}} {{angbr|sklērós}}, meaning "hard", and {{lang|grc|κάρυον}} {{angbr|káryon}}, "nut", in reference to the stone inside the fleshy fruit), commonly known as the marula, is a medium-sized deciduous fruit-bearing tree, indigenous to the miombo woodlands of Southern Africa, the Sudano-Sahelian range of West Africa, the savanna woodlands of East Africa and Madagascar.

Description

The tree is a single-stemmed species with a broad, spreading crown. It is distinguished by its grey mottled bark and can grow up to 18 meters tall, primarily in low altitudes and open woodlands. The distribution of this species throughout Africa and Madagascar has followed the Bantu in their migrations. There is some evidence of human domestication of marula trees, as trees found on farm lands tend to have larger fruit size.{{Cite journal|last1=Leakey|first1=Roger|last2=Shackleton|first2=Sheona|last3=Du Plessis|first3=Pierre|date=2005|title=Domestication potential of Marula (Sclerocarya birrea subsp caffra) in South Africa and Namibia: 1. Phenotypic variation in fruit traits|journal=Agroforestry Systems|volume=64|issue=1|pages=25–35|doi=10.1007/s10457-005-2419-z|bibcode=2005AgrSy..64...25L |s2cid=21601141}}

The fruits, which ripen between December and March, have a light yellow skin (exocarp), with white flesh (mesocarp). They fall to the ground when unripe and green in colour, and then ripen to a yellow colour on the ground. They are succulent and tart with a strong and distinctive flavour.{{cite book |last=Wickens |first=G. E. |author2=Food and Agriculture Organization |title=Edible Nuts |url=http://www.fao.org/docrep/V8929E/v8929e00.htm |access-date=2008-11-10 |series=Non-Wood Forest Products |volume=5 |year=1995 |publisher=Food and Agriculture Organization |location=Rome |isbn=92-5-103748-5 |oclc=34529770 |chapter=Potential Edible Nuts |chapter-url=http://www.fao.org/docrep/V8929E/v8929e06.htm|author2-link=Food and Agriculture Organization }} Inside is a walnut-sized, thick-walled stone (endocarp). These stones, when dry, expose the seeds by shedding 2 (sometimes 3) small circular plugs at one end. The fruits are drupes with a single seed encased within their endocarp, although up to four seeds can be present.{{Cite web|url=https://uses.plantnet-project.org/en/Sclerocarya_birrea_(PROTA)|title=Sclerocarya birrea|date=15 May 2018|access-date=19 April 2019}} The seeds have a delicate nutty flavour and are much sought-after, especially by small rodents who know to gnaw exactly where the plugs are located.

The trees are dioecious. Male trees produce multiple male flowers on a terminal raceme. These have red sepals and petals, and about 20 stamens per flower. On rare occasions a male flower can produce a gynoecium, turning it bisexual. Female flowers grow individually on their own pedicel and have staminodes. The leaves are alternate, compound, and imparipinnately divided. The leaflet shapes range from round to elliptical.

Taxonomy and etymology

Sclerocarya birrea is divided into three subspecies: subsp. birrea, subsp. afra and subsp. multifoliolata. These subspecies are differentiated by changes in leaf shape and size. Subsp. birrea is found in northern Africa, subsp. afra is found in southern Africa, and subsp. multifoliolata is only found in Tanzania.

The generic name Sclerocarya is derived from the Ancient Greek words 'skleros' meaning 'hard' and 'karyon' meaning 'nut'. This refers to the hard pit of the fruit. The specific epithet 'birrea' comes from the common name 'birr', for this type of tree in Senegal. The marula belongs to the same family, Anacardiaceae, as the mango, cashew, pistachio and sumac, and is closely related to the genus Poupartia from Madagascar.

Common names include jelly plum, cat thorn, morula, cider tree, marula, maroola nut/plum, and in Afrikaans, maroela.{{cite web

|url = http://www2.dwaf.gov.za/dwaf/cmsdocs/4116___poster%20protected%20trees.pdf

|title = Protected Trees

|date = 3 May 2013

|publisher = Department of Water Affairs and Forestry, Republic of South Africa

|url-status = dead

|archive-url = https://web.archive.org/web/20100705085122/http://www2.dwaf.gov.za/dwaf/cmsdocs/4116___poster%20protected%20trees.pdf

|archive-date = 5 July 2010

}}

Subspecies

Three subspecies are accepted:

Sclerocarya birrea subsp. afra {{small|(Sond.) Kokwaro}} – Kenya to Namibia and KwaZulu-Natal, Madagascar, and Mayotte
Sclerocarya birrea subsp. birrea – West Africa to Ethiopia and Tanzania
Sclerocarya birrea subsp. multifoliolata {{small|(Engl.) Kokwaro}} – Tanzania

Uses

=Traditional uses=

The fruit is traditionally used for food in Africa, and has considerable socioeconomic importance.{{cite book |author-link=United States National Research Council |author=National Research Council |title=Lost Crops of Africa: Volume III: Fruits |url=http://books.nap.edu/openbook.php?record_id=11879 |access-date=2008-07-17 |volume=3 |date=2008-01-25 |publisher=National Academies Press |location=Washington, D.C. |isbn=978-0-309-10596-5 |oclc=34344933 |chapter=Marula |chapter-url=http://books.nap.edu/openbook.php?record_id=11879&page=117}} The fruit juice and pulp are mixed with water and stored in a container over 1–3 days of fermentation to make marula beer, a traditional alcoholic beverage.{{Cite web|url=https://www.ecoproducts.co.za/marvellous-brewers-marula-beer/|title=The marvellous brewers of marula beer|date=2016-03-14|publisher=Eco products|language=en-US|access-date=2019-02-14}} The alcoholic distilled beverage (morula) made from the fruit is referenced in the stories of the South African writer Herman Charles Bosman.{{Citation needed|date=June 2019}} Marula oil is used topically to moisturise the skin, and as an edible oil in the diet of San people in Southern Africa.{{cite journal

| author=Engelter & Wehmeyer

| year=1970

| title=Fatty acid composition of oils of some edible seeds of wild plants

| journal=Journal of Agricultural and Food Chemistry

| volume=18

| issue=1

| pages=25–26

| doi=10.1021/jf60167a025

| pmid=5524461

| last2=Wehmeyer

| first2=A.S.

| bibcode=1970JAFC...18...25E

}}{{cite book

| author=Shackleton, S.E.| year=2002

| title=A summary of knowledge on Sclerocarya birrea with emphasis on its importance as a NTFP in South and Southern Africa

| work=Part 1

|display-authors=etal}} The marula tree is protected in South Africa.

=Commercial uses=

On an industrial level the fruit of the marula tree is collected from the wild by members of rural communities on whose land the trees grow. This harvest and sale of fruit only occur over two to three months, but is an important source of income to poor rural people, especially women.{{Cite journal|last=Sheona|first=Shackleton|date=2004|title=Livelihood benefits from the local level commercialization of savanna resources: a case study of the new and expanding trade in marula (Sclerocarya birrea) beer in Bushbuckridge, South Africa|url=https://www.ingentaconnect.com/content/sabinet/sajsci/2004/00000100/00000011/art00031|journal=South African Journal of Science|volume=100|issue=11|pages=651–657|via=ingenta}} The fruit is delivered to processing plants where fruit pulp, pips, kernels and kernel oil are extracted and stored for processing throughout the year.{{Citation needed|date=June 2019}}

=Uses by other species=

The marula fruit is eaten by various animals in Southern Africa. Giraffes, rhinoceroses and elephants all browse on the marula tree, with elephants in particular being a major consumer. Elephants eat the bark, branches and fruits of the marula, which may limit the spread of the trees. The damaged bark, due to browsing, can be used to identify marula trees as elephants preferentially target them. Elephants distribute marula seeds in their dung.{{cite journal |last1=Morris |first1=Steve |last2=Humphreys |first2=David |last3=Reynolds |first3=Dan |date=2006 |title=Myth, Marula, and Elephant: An Assessment of Voluntary Ethanol Intoxication of the African Elephant (Loxodonta africana) Following Feeding on the Fruit of the Marula Tree (Sclerocarya birrea) |url=http://www.bio.bris.ac.uk/research/morlab/Morris%20et%20al%20%5BPBZ%5D%202006.pdf |journal=Physiological and Biochemical Zoology |volume=79 |issue=2 |pages=363–369 |doi=10.1086/499983 |pmid=16555195 |access-date=26 October 2015 |s2cid=36629801}} In the documentary Animals Are Beautiful People by Jamie Uys, released in 1974, some scenes portray elephants, ostriches, warthogs and baboons allegedly becoming intoxicated from eating fermented marula fruit, as do reports in the popular press.{{cite web|last=Couper|first=Ross|title=Elephants drunk on native fruit at South Africa's Singita Sabi Sand|date=24 April 2014 |url=https://news.yahoo.com/photos/elephants-drunk-on-native-fruit-at-south-africa-s-singita-sabi-sand-1398369057-slideshow/|access-date=25 April 2014}} While the fruit is commonly eaten by elephants, the animals would need a huge amount of fermented marulas to have any effect on them, and other animals prefer the ripe fruit.

The marula fruit has been suggested to be the food of choice for the ancestral forest-dwelling form of the fruit fly Drosophila melanogaster, which was much more selective about which fruit they preferred than the flies that have self-domesticated to live near to humans. The ancestral fruit flies are triggered by the ester ethyl isovalerate in the marula fruit.{{cite journal |last1=Mansourian |first1=Suzan |last2=Enjin |first2=Anders V. |last3=Jirle |first3=Erling |last4=Ramesh |first4=Vedika |last5=Rehermann |first5=Guillermo |last6=Becher |first6=Paul G. |last7=Pool |first7=John E. |last8=Stensmyr |first8=Marcus C. |date=December 6, 2018 |title=Wild African Drosophila melanogaster Are Seasonal Specialists on Marula Fruit |url= |journal=Cell |volume=28 |issue=24 |pages=3960–3968.e3 |doi=10.1016/j.cub.2018.10.033 |pmc=7065024 |pmid=30528579|bibcode=2018CBio...28E3960M }}