Persea Temporal range: | |
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Persea indica foliage and fruit | |
Avocado (Persea americana) foliage | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Magnoliids |
Order: | Laurales |
Family: | Lauraceae |
Genus: | Persea Mill. [2] |
Type species | |
Persea americana | |
Species | |
See text. Complete list | |
Synonyms | |
Persea is a genus of about 150 species of evergreen trees belonging to the laurel family, Lauraceae. [3] The best-known member of the genus is the avocado, P. americana, widely cultivated in subtropical regions for its large, edible fruit.
They are medium-size trees, 15–30 m (49.2–98.4 ft) tall at maturity. The leaves are simple, lanceolate to broad lanceolate, varying with species from 5–30 cm (1.97–11.81 in) long and 2–12 cm (0.79–4.72 in) broad, and arranged spirally or alternately on the stems. The flowers are in short panicles, with six small greenish-yellow perianth segments 3–6 mm (0.12–0.24 in) long, nine stamens and an ovary with a single embryo. The fruit is an oval or pear-shaped berry, [4] with a fleshy outer covering surrounding the single seed; size is very variable among the species, from 1–1.5 cm (0.39–0.59 inches) in e.g. P. borbonia and P. indica, up to 10–20 cm (3.94–7.87 inches) in some cultivars of P. americana.
The species of Persea have a disjunct distribution, with about 70 Neotropical species, ranging from Brazil and Chile in South America to Central America and Mexico, the Caribbean, and the southeastern United States; a single species, P. indica, endemic to Madeira and the Canary Islands off northwest Africa; and 80 species inhabiting east and southeast Asia. None of the species are very tolerant of severe winter cold, with the hardiest, P. borbonia, P. ichangensis and P. lingue, surviving temperatures down to about −12 °C (10.4 °F); 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; for example, P. lingue in Central Chile.
The family Lauraceae was part of the land flora of Gondwana, and many genera had migrated to South America via Antarctica over ocean landbridges by the time of the Paleocene. From South America they spread over most of the continent. When the North American and South American tectonic plates joined in the late Neogene, 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, others, which also reached South America and Mesoamerica, such as Beilschmiedia and Nectandra are still surviving today in Africa in a number of species. The genus, however, died out in Africa, except for P. indica , which is, today, a threatened species that survives in the fog-shrouded mountains of the Canary Islands and Madeira.
Fossil evidence indicates that the genus originated in West Africa during the Paleocene, and spread to Asia, to South America, and to Europe and thence to North America. It is thought that the gradual drying of Africa, west Asia, and the Mediterranean from the Oligocene to the Pleistocene, and the glaciation of Europe 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 quetzals, 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 avocado. 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 21 mm (0.83 in), 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 100 meters (328 ft) 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. [5]
Persea species are also used as food plants by the larvae of some Lepidoptera species including giant leopard moth, Coleophora octagonella (which feeds exclusively on P. carolinensis) and Hypercompe indecisa .
The genus Persea is treated in three subgenera. The Asian subgenus Machilus is treated in a separate genus Machilus by many authors, including in the Flora of China, while graft-incompatibility between subgenus Persea and subgenus Eriodaphne suggests that these too may be better treated as distinct genera, in fact Kostermans (1993) founded the genus Mutisiopersea for these. Another closely related genus, Beilschmiedia , is also sometimes included in Persea.
In a phylogenetic analysis of the "Persea group", which also includes Alseodaphne , Phoebe, Nothaphoebe, Dehaasia and Apollonias, Persea was found to be mostly monophyletic, with Apollonias barbujana from the Canary Islands nested within the core Persea group. The species Perseanudigemma was found to be more closely related to Phoebe, while Persea sphaerocarpa was found to be nested within a group of Alseodaphne species. [6]
Based on [6]
| Machias clade Alseodaphne-Dehaasia clade Persea clade Phoebe clade Alseodaphne-Persea group Outgroups | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Philip Miller derived Persea from the Greek name Περσέα. It was applied by Theophrastus and Hippocrates to an uncertain Egyptian tree, possibly Cordia myxa or a Mimusops species. [8]
The avocado, alligator pear or avocado pear is a medium-sized, evergreen tree in the laurel family (Lauraceae). It is native to the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. It was prized for its large and unusually oily fruit. The tree likely originated in the highlands bridging south-central Mexico and Guatemala. Avocado trees have a native growth range from Mexico to Costa Rica. Its fruit, sometimes also referred to as an alligator pear or avocado pear, is botanically a large berry containing a single large seed. Sequencing of its genome showed that the evolution of avocados was shaped by polyploidy events and that commercial varieties have an hybrid origin. Avocado trees are partly self-pollinating, and are often propagated through grafting to maintain consistent fruit output. Avocados are presently cultivated in the tropical and Mediterranean climates of many countries. Mexico is the world's leading producer of avocados as of 2020, supplying nearly 30% of the global harvest in that year.
Lauraceae, or the laurels, is a plant family that includes the true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genera worldwide. They are dicotyledons, and occur mainly in warm temperate and tropical regions, especially Southeast Asia and South America. Many are aromatic evergreen trees or shrubs, but some, such as Sassafras, are deciduous, or include both deciduous and evergreen trees and shrubs, especially in tropical and temperate climates. The genus Cassytha is unique in the Lauraceae in that its members are parasitic vines. Most laurels are highly poisonous.
Laurel forest, also called laurisilva or laurissilva, is a type of subtropical forest found in areas with high humidity and relatively stable, mild temperatures. The forest is characterized by broadleaf tree species with evergreen, glossy and elongated leaves, known as "laurophyll" or "lauroid". Plants from the laurel family (Lauraceae) may or may not be present, depending on the location.
Ocotea is a genus of flowering plants belonging to the family Lauraceae. Many are evergreen trees with lauroid leaves.
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 Philippines. It is sometimes included in the genus Persea, and currently includes about 100 species.
Phoebe is a genus of evergreen trees and shrubs belonging to the Laurel family, Lauraceae. There are 75 accepted species in the genus, distributed in tropical and subtropical Asia and New Guinea. 35 species occur in China, of which 27 are endemic. The first description of the genus was of the type species P. lanceolata made in 1836 by Christian Gottfried Daniel Nees von Esenbeck in Systema Laurinarum, p. 98.
Persea schiedeana, the coyo, is an endangered, evergreen tree in the laurel family (Lauraceae), native to tropical forests of southern Mexico and Central America. Its edible fruit resembles that of the avocado, a related tree in the genus Persea. Other common names include aguacate de montaña, aguacatón, chinini, chupte and yas.
Aniba is an American neotropical flowering plant genus in the family Lauraceae. They are present in low and mountain cloud forest in Caribbean islands, Central America, and northern to central South America.
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 Zealand, North America, Central America, the Caribbean, and South America. The best-known species to gardeners in temperate areas are B. berteroana and B. miersii because of their frost tolerance. Seeds of B. bancroftii were used as a source of food by Australian Aborigines. Timbers of some species are very valuable.
Licaria is a flowering plant genus in the family Lauraceae, native to Central America and South America. It is a Neotropical genus with around 80 species.
Nectandra is a genus of plant in the family Lauraceae. They are primarily Neotropical, with Nectandra coriacea being the only species reaching the southernmost United States. They have fruit with various medical effects. Sweetwood is a common name for some plants in this genus.
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. It is threatened by habitat loss.
Persea lingue, synonyms including Persea meyeniana, is an evergreen tree or shrub in the laurel family (Lauraceae), found in Argentina and Chile. It belongs to the genus Persea, a group of evergreen trees including the avocado. P. lingue was historically used in leather production, and is currently threatened by habitat loss.
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 not more than 40 feet tall, with bark separated into scales by fissures across its surface. Mature leaves are green, paler on their undersides, which have prominent brownish or reddish-brown hairs. The species prefers swamps and coastal areas, particularly locations with moist, peat-rich soil. It is sensitive to the fungal disease known as laurel wilt, even more so than related species.
Apollonias barbujana, the Canary laurel or barbusano, is perhaps the only species of flowering plants belonging to the genus Apollonias of the laurel family, Lauraceae. It is endemic to the Macaronesian islands of Madeira and the Canary Islands. Molecular phylogenies have found that the species is nested within the genus Persea, closely related to Persea americana (avocado).
Persea borbonia or redbay is a small, evergreen tree in the laurel family (Lauraceae), native to the southeastern United States. It belongs to the genus Persea, a group of evergreen trees including bays and the avocado. Persea borbonia has several common names including tisswood, scrubbay, shorebay, and swampbay.
Kubitzia is an American neotropical flowering plant genus in the family Lauraceae with two species from South America.
Machilus wangchiana is a tree of the Lauraceae family and is an avocado species endemic to China.