''Persea'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of about 111 species of

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

trees In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only p ...

belonging to the laurel family,

Lauraceae Lauraceae, or the laurels, is a plant Family (biology), family that includes the bay laurel, true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genus (biology), genera worldwide. They are dicotyled ...

. The best-known member of the genus is the

avocado The avocado, alligator pear or avocado pear (''Persea americana'') is an evergreen tree in the laurel family (Lauraceae). It is native to Americas, the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. It was priz ...

, ''P. americana'', widely cultivated in

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

regions for its large, edible

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

Overview

They are medium-size trees, tall at maturity. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are simple, lanceolate to broad lanceolate, varying with species from long and broad, and arranged spirally or alternately on the stems. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are in short panicles, with six small greenish-yellow perianth segments long, nine stamens and an ovary with a single embryo. The

is an oval or pear-shaped

berry A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit although many pips or seeds may be present. Common examples of berries in the cul ...

, with a fleshy outer covering surrounding the single

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

; size is very variable among the species, from in e.g. ''P. indica'', up to in some cultivars of ''P. americana''.

Distribution and ecology

The species of ''Persea'' have a disjunct distribution, with about 109

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

species, ranging from

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

and

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, and the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

; with two species, '' P. indica'' and '' P. barbujana'', native to

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

and the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

off northwest Africa. None of the species are very tolerant of severe winter cold, with the hardiest, '' P. lingue'', surviving temperatures down to about ; they also require continuously moist soil, and do not tolerate drought. A number of these species are found in forests that face threats of destruction or

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

, including ''P. lingue'' in central Chile. The family

was part of the land flora of

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

, and many genera had migrated to South America via

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

over ocean landbridges by the time of the

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

. From South America they spread over most of the continent. When the North American and South American tectonic plates joined in the late

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

, volcanic mountain building created island chains which later formed the Mesoamerican landbridge. Pliocene elevation created new habitats for speciation. While some genera died out in increasingly xerophytic mainland Africa, starting with the freezing of Antarctica about 20 million years ago and the formation of the

Benguela current The Benguela Current is the broad, northward flowing ocean current that forms the eastern portion of the South Atlantic Ocean gyre. The current extends from roughly Cape Point in the south, to the position of the Angola-Benguela Front in the no ...

, others, which also reached South America and Mesoamerica, such as ''

Beilschmiedia ''Beilschmiedia'' is a genus of trees and shrubs in family Lauraceae. Most of its species grow in tropical climates, but a few of them are native to temperate regions, and they are widespread in tropical Asia, Africa, Madagascar, Australia, New Z ...

'' and '' Nectandra'' are still surviving today in Africa in a number of species. The genus, however, died out in Africa, except for '' P. indica'' and '' P. barbujana'', which survive in the fog-shrouded mountains of the

and

. Fossil evidence indicates that the genus originated in

West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

during the

, and spread to Asia, to South America, and to Europe and thence to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It is thought that the gradual drying of Africa, west Asia, and the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

from the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

to the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

, and the

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

during the Pleistocene, caused the extinction of the genus across these regions, resulting in the present distribution. Since this habitat is constantly threatened by encroaching agriculture, the laurel forest animal or vegetal species have already become rare in many of its former habitats and are threatened by further habitat loss. In Mesoamerica, ''Persea'' proliferated into many new species, and the berries of some of them constitute a valuable food supply for

quetzal Quetzals () are strikingly colored birds in the trogon family. They are found in forests, especially in humid highlands, with the five species from the genus ''Pharomachrus'' being exclusively Neotropical, while a single species, the eared quet ...

s, trogoniform birds that live in the montane rainforests of Mesoamerica. In particular, the resplendent quetzal's favorite fruits are berries of wild relatives of the

. Their differing maturing times in the cloudforest determine the migratory movements of the quetzals to differing elevation levels in the forests. With a gape width of , the quetzal swallows the small berry (aguacatillo) whole, which he catches while flying through the lower canopy of the tree, and then regurgitates the seed within from the tree. Wheelright in 1983 observed that parent quetzals take far less time intervals to deliver fruits to the young brood than insects or lizards, reflecting the ease of procuring fruits, as opposed to capturing animal prey. Since the young are fed exclusively berries in the first 2 weeks after hatching, these berries must be of high nutritional value. Usually only the total percentage of water, sugar, nitrogen, crude fats and carbohydrates are reported by ornithologists. ''Persea'' species are also used as food plants by the

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e of some

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

species including

giant leopard moth The giant leopard moth (''Hypercompe scribonia'') is a moth of the family Erebidae. They are distributed through North America from southern Ontario, and southern and eastern United States through New England, Mexico, and south to Colombia. The ...

, '' Coleophora octagonella'' (which feeds exclusively on ''P. carolinensis'') and '' Hypercompe indecisa''.

Classification

The genus ''Persea'' includes two subgenera, ''Persea'' and ''Eriodaphne''. Graft-incompatibility and morphological and phylogenetic differences between subgenus ''Persea'' and subgenus ''Eriodaphne'' suggests that these too may be better treated as distinct genera. Kostermans (1993) founded the genus ''Mutisiopersea'' for these. Some authors place ''

Persea barbujana ''Persea barbujana'', the Canary laurel or barbusano, is a species of tree in the laurel family, Lauraceae. It is endemic to the Macaronesian islands of Madeira (incl. Porto Santo) and the Canary Islands. It is often placed as the sole species i ...

'' from the Canary Islands in a separate genus ''Apollonias'', but phylogenetic studies place it within subgenus ''Eriodaphne''. The genus '' Tamala'' is included in ''Persea'' by many authors, and some authors treat the Asian genus ''

Machilus ''Machilus'' is a genus of flowering plants in the family Lauraceae. It is found in temperate, subtropical, and tropical forest, occurring in China, Korea, Japan, Taiwan, Indochina, the Indian subcontinent, Malaysia, Indonesia, and the Phili ...

'' as a subgenus of ''Persea''. Another closely related genus, ''

'', is also sometimes included in ''Persea''. In a phylogenetic analysis of the "''Persea'' group", which also includes '' Alseodaphne'', '' Dehaasia'', ''

'', '' Nothaphoebe'', and '' Phoebe'', ''Persea'' was found to be mostly monophyletic. The species '' Persea nudigemma'' was found to be more closely related to ''Phoebe'', while '' Persea sphaerocarpa'' was found to be nested within a group of '' Alseodaphne'' species. Avocado Hass - single and halved

;Subgenus ''Persea'' —

. Two species. *''

Persea americana The avocado, alligator pear or avocado pear (''Persea americana'') is an evergreen tree in the laurel family (Lauraceae). It is native to Americas, the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. It was priz ...

'' Mill. – Avocado **''Persea americana'' var. ''drymifolia'' (Schltdl. & Cham.) S.F.Blake **''Persea americana'' var. ''floccosa'' (Mez) Scora **''Persea americana'' var. ''guatemalensis'' (L.O.Williams) Scora **''Persea americana'' var. ''nubigena'' (L.O.Williams) L.E.Kopp **''Persea americana'' var. ''steyermarkii'' (C.K.Allen) Scora *'' Persea schiedeana'' Nees – Coyo ;Subgenus ''Eriodaphne'' (''Mutisiopersea'') —

The Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.'' Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sin ...

and

Macaronesia Macaronesia (; ) is a collection of four volcanic archipelagos in the Atlantic Ocean#North Atlantic, North Atlantic Ocean, off the coast of North Africa and Europe. Each archipelago is made up of a number of list of islands in the Atlantic Oc ...

. About 109 species, including: *'' Persea alpigena'' *'' Persea brevipetiolata'' van der Werff – from Mexico *'' Persea caerulea'' (Ruiz & Pav.) Mez *'' Persea cinerascens'' *'' Persea donnell-smithii'' Mez *''

Persea indica ''Persea indica'' is a large, evergreen tree in the laurel family (Lauraceae), native to humid uplands on Madeira and the Canary Islands in the North Atlantic. It belongs to the genus '' Persea'', a group of evergreen trees including the avocado. ...

'' (L.) Spreng. – Viñátigo *'' Persea lingue'' (Ruiz & Pav.) Nees – Lingue *'' Persea longipes'' (Schltdl.) Meisn. *''

Persea palustris ''Persea palustris'', also known as swamp bay or swampbay, is a small tree or shrub found throughout the Southeastern United States and the Bahamas, with much of its range overlapping with that of its relative '' Persea borbonia''. It is generally ...

'' (Raf.) Sarg. – Swampbay

Formerly placed here

*'' Cinnamodendron cinnamomifolium'' (Kunth) Kosterm. (as ''P. cinnamomifolia'' Kunth or ''P. mexicana'' (Meisn.) Hemsl.) *'' Laurus azorica'' (Seub.) Franco (as ''P. azorica'' Seub.) *'' Tamala borbonia'' (as ''Persea borbonia'' ) *'' Tamala humilis'' (as ''Persea humilis'' ) *'' Tamala palustris'' (as ''Persea palustris'' )

Phylogeny

Based on

Etymology

Philip Miller derived ''Persea'' from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

name . It was applied by

Theophrastus Theophrastus (; ; c. 371 – c. 287 BC) was an ancient Greek Philosophy, philosopher and Natural history, naturalist. A native of Eresos in Lesbos, he was Aristotle's close colleague and successor as head of the Lyceum (classical), Lyceum, the ...

and

Hippocrates Hippocrates of Kos (; ; ), also known as Hippocrates II, was a Greek physician and philosopher of the Classical Greece, classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referr ...

to an uncertain Egyptian tree, possibly '' Cordia myxa'' or a '' Mimusops'' species.

References

Bibliography

* André Joseph Guillaume Henri Kostermans. 1993. Mutisiopersea Kostermans, a new genus in Lauraceae. ''Rheedea'' 3: 132–135. *C. Michael Hogan. 2008
''Chilean Wine Palm: Jubaea chilensis'', GlobalTwitcher.com, ed. Nicklas Stromberg
*Lucille E. Kopp. 1966. "A taxonomic revision of the genus Persea in the Western Hemisphere (''Persea-Lauracese'')" ''Memoirs of the New York Botanical Garden'' 14(1): pp. 1–117

External links

Avocado source
Extensive information on the

Avocado The avocado, alligator pear or avocado pear (''Persea americana'') is an evergreen tree in the laurel family (Lauraceae). It is native to Americas, the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. It was priz ...

and the genus generally, particularly the subgenera ''Persea'' and ''Eriodaphne''
Flora of North America: ''Persea''Flora of China: ''Machilus''
Full list of species in ''Machilus'' in China {{Authority control Lauraceae genera Taxa named by Philip Miller