|Coconut (Cocos nucifera) in Martinique|
|Family:|| Arecaceae |
Bercht. & J.Presl, nom. cons.
|Well over 2600 species in some 202 genera|
The Arecaceae is a family of perennial flowering plants in the monocot order Arecales. Their growth form can be climbers, shrubs, tree-like and stemless plants, all commonly known as palms. Those having a tree-like form are called palm trees.Currently 181 genera with around 2,600 species are known, most of them restricted to tropical and subtropical climates. Most palms are distinguished by their large, compound, evergreen leaves, known as fronds, arranged at the top of an unbranched stem. However, palms exhibit an enormous diversity in physical characteristics and inhabit nearly every type of habitat within their range, from rainforests to deserts.
Palms are among the best known and most extensively cultivated plant families. They have been important to humans throughout much of history. Many common products and foods are derived from palms. In contemporary times, palms are also widely used in landscaping, making them one of the most economically important plants. In many historical cultures, because of their importance as food, palms were symbols for such ideas as victory, peace, and fertility. For inhabitants of cooler climates today, palms symbolize the tropics and vacations.
The word Arecaceae is derived from the word areca with the suffix "-aceae". [ citation needed ]Areca is derived from Portuguese, via Malayalam അടയ്ക്ക (aṭaykka), which is from Proto-Dravidian *aṭ-ay-kkāy (“areca nut”). The suffix -aceae is the feminine plural of the Latin -āceus ("resembling").
Whether as shrubs, tree-like, or vines, palms have two methods of growth: solitary or clustered. The common representation is that of a solitary shoot ending in a crown of leaves. This monopodial character may be exhibited by prostrate, trunkless, and trunk-forming members. Some common palms restricted to solitary growth include Washingtonia and Roystonea . Palms may instead grow in sparse though dense clusters. The trunk develops an axillary bud at a leaf node, usually near the base, from which a new shoot emerges. The new shoot, in turn, produces an axillary bud and a clustering habit results. Exclusively sympodial genera include many of the rattans, Guihaia , and Rhapis . Several palm genera have both solitary and clustering members. Palms which are usually solitary may grow in clusters and vice versa. These aberrations suggest the habit operates on a single gene.
Palms have large, evergreen leaves that are either palmately ('fan-leaved') or pinnately ('feather-leaved') compound and spirally arranged at the top of the stem. The leaves have a tubular sheath at the base that usually splits open on one side at maturity.The inflorescence is a spadix or spike surrounded by one or more bracts or spathes that become woody at maturity. The flowers are generally small and white, radially symmetric, and can be either uni- or bisexual. The sepals and petals usually number three each, and may be distinct or joined at the base. The stamens generally number six, with filaments that may be separate, attached to each other, or attached to the pistil at the base. The fruit is usually a single-seeded drupe (sometimes berry-like) but some genera (e.g., Salacca ) may contain two or more seeds in each fruit.
Like all monocots, palms do not have the ability to increase the width of a stem (secondary growth) via the same kind of vascular cambium found in non-monocot woody plants.This explains the cylindrical shape of the trunk (almost constant diameter) that is often seen in palms, unlike in ring-forming trees. However, many palms, like some other monocots, do have secondary growth, although because it does not arise from a single vascular cambium producing xylem inwards and phloem outwards, it is often called "anomalous secondary growth".
The Arecaceae are notable among monocots for their height and for the size of their seeds, leaves, and inflorescences. Ceroxylon quindiuense , Colombia's national tree, is the tallest monocot in the world, reaching up to 60 m tall. The coco de mer (Lodoicea maldivica) has the largest seeds of any plant, 40–50 cm in diameter and weighing 15–30 kg each (coconuts are the second largest). Raffia palms ( Raphia spp.) have the largest leaves of any plant, up to 25 m long and 3 m wide. The Corypha species have the largest inflorescence of any plant, up to 7.5 m tall and containing millions of small flowers. Calamus stems can reach 200 m in length.
Most palms are native to tropical and subtropical climates. Palms thrive in moist and hot climates but can be found in a variety of different habitats. Their diversity is highest in wet, lowland forests. South America, the Caribbean, and areas of the south Pacific and southern Asia are regions of concentration. Colombia may have the highest number of palm species in one country. There are some palms that are also native to desert areas such as the Arabian peninsula and parts of northwestern Mexico. Only about 130 palm species naturally grow entirely beyond the tropics, mostly in humid lowland subtropical climates, in highlands in southern Asia, and along the rim lands of the Mediterranean Sea. The northernmost native palm is Chamaerops humilis , which reaches 44°N latitude along the coast of Liguria, Italy.In the southern hemisphere, the southernmost palm is the Rhopalostylis sapida , which reaches 44°S on the Chatham Islands where an oceanic climate prevails. Cultivation of palms is possible north of subtropical climates, and some higher latitude locales such as Ireland, Scotland, England, and the Pacific Northwest feature a few palms in protected locations and microclimates.
Palms inhabit a variety of ecosystems. More than two-thirds of palm species live in humid moist forests, where some species grow tall enough to form part of the canopy and shorter ones form part of the understory. m, such as those in the genus Ceroxylon native to the Andes. Palms may also live in grasslands and scrublands, usually associated with a water source, and in desert oases such as the date palm. A few palms are adapted to extremely basic lime soils, while others are similarly adapted to extreme potassium deficiency and toxicity of heavy metals in serpentine soils.Some species form pure stands in areas with poor drainage or regular flooding, including Raphia hookeri which is common in coastal freshwater swamps in West Africa. Other palms live in tropical mountain habitats above 1000
Palms are a monophyletic group of plants, meaning the group consists of a common ancestor and all its descendants.Extensive taxonomic research on palms began with botanist H.E. Moore, who organized palms into 15 major groups based mostly on general morphological characteristics. The following classification, proposed by N.W. Uhl and J. Dransfield in 1987, is a revision of Moore's classification that organizes palms into six subfamilies.
A few general traits of each subfamily are listed below.
The Coryphoideae are the most diverse subfamily, and are a paraphyletic group, meaning all members of the group share a common ancestor, but the group does not include all the ancestor's descendants. Most palms in this subfamily have palmately lobed leaves and solitary flowers with three, or sometimes four carpels. The fruit normally develops from only one carpel.
Subfamily Calamoideae includes the climbing palms, such as rattans. The leaves are usually pinnate; derived characters (synapomorphies) include spines on various organs, organs specialized for climbing, an extension of the main stem of the leaf-bearing reflexed spines, and overlapping scales covering the fruit and ovary.
Subfamily Nypoideae contains only one species, Nypa fruticans,which has large, pinnate leaves. The fruit is unusual in that it floats, and the stem is dichotomously branched, also unusual in palms.
Subfamily Ceroxyloideae has small to medium-sized flowers, spirally arranged, with a gynoecium of three joined carpels.
The Arecoideae are the largest subfamily, with six diverse tribes (Areceae, Caryoteae, Cocoseae, Geonomateae, Iriarteeae, and Podococceae) containing over 100 genera. All tribes have pinnate or bipinnate leaves and flowers arranged in groups of three, with a central pistillate and two staminate flowers.
The Phytelephantoideae are a monoecious subfamily. Members of this group have distinct monopodial flower clusters. Other distinct features include a gynoecium with five to 10 joined carpels, and flowers with more than three parts per whorl. Fruits are multiple-seeded and have multiple parts.
Currently, few extensive phylogenetic studies of the Arecaceae exist. In 1997, Baker et al. explored subfamily and tribe relationships using chloroplast DNA from 60 genera from all subfamilies and tribes. The results strongly showed the Calamoideae are monophyletic, and Ceroxyloideae and Coryphoideae are paraphyletic. The relationships of Arecoideae are uncertain, but they are possibly related to the Ceroxyloideae and Phytelephantoideae. Studies have suggested the lack of a fully resolved hypothesis for the relationships within the family is due to a variety of factors, including difficulties in selecting appropriate outgroups, homoplasy in morphological character states, slow rates of molecular evolution important for the use of standard DNA markers, and character polarization.However, hybridization has been observed among Orbignya and Phoenix species, and using chloroplast DNA in cladistic studies may produce inaccurate results due to maternal inheritance of the chloroplast DNA. Chemical and molecular data from non-organelle DNA, for example, could be more effective for studying palm phylogeny.
This section needs additional citations for verification .(January 2016)
The Arecaceae are the first modern family of monocots appearing in the fossil record around 80 million years ago (Mya), during the late Cretaceous period. The first modern species, such as Nypa fruticans and Acrocomia aculeata , appeared 69 Mya, as evidenced by fossil Nypa pollen. Palms appear to have undergone an early period of adaptive radiation. By 60 Mya, many of the modern, specialized genera of palms appeared and became widespread and common, much more widespread than their range today. Because palms separated from the monocots earlier than other families, they developed more intrafamilial specialization and diversity. By tracing back these diverse characteristics of palms to the basic structures of monocots, palms may be valuable in studying monocot evolution. Several species of palms have been identified from flowers preserved in amber, including Palaeoraphe dominicana and Roystonea palaea . Evidence can also be found in samples of petrified palmwood.
Human use of palms is at least as old as human civilization itself, starting with the cultivation of the date palm by Mesopotamians and other Middle Eastern peoples 5000 years or more ago.Date wood, pits for storing dates, and other remains of the date palm have been found in Mesopotamian sites. The date palm had a tremendous effect on the history of the Middle East. W.H. Barreveld wrote:
One could go as far as to say that, had the date palm not existed, the expansion of the human race into the hot and barren parts of the "old" world would have been much more restricted. The date palm not only provided a concentrated energy food, which could be easily stored and carried along on long journeys across the deserts, it also created a more amenable habitat for the people to live in by providing shade and protection from the desert winds (Fig. 1). In addition, the date palm also yielded a variety of products for use in agricultural production and for domestic utensils, and practically all parts of the palm had a useful purpose.
An indication of the importance of palms in ancient times is that they are mentioned more than 30 times in the Bible,and at least 22 times in the Quran.
Arecaceae have great economic importance, including coconut products, oils, dates, palm syrup, ivory nuts, carnauba wax, rattan cane, raffia, and palm wood.
Along with dates mentioned above, members of the palm family with human uses are numerous.
Like many other plants, palms have been threatened by human intervention and exploitation. The greatest risk to palms is destruction of habitat, especially in the tropical forests, due to urbanization, wood-chipping, mining, and conversion to farmland. Palms rarely reproduce after such great changes in the habitat, and those with small habitat ranges are most vulnerable to them. The harvesting of heart of palm, a delicacy in salads, also poses a threat because it is derived from the palm's apical meristem, a vital part of the palm that cannot be regrown (except in domesticated varieties, e.g. of peach palm).The use of rattan palms in furniture has caused a major population decrease in these species that has negatively affected local and international markets, as well as biodiversity in the area. The sale of seeds to nurseries and collectors is another threat, as the seeds of popular palms are sometimes harvested directly from the wild. In 2006, at least 100 palm species were considered endangered, and nine species have been reported as recently extinct.
However, several factors make palm conservation more difficult. Palms live in almost every type of warm habitat and have tremendous morphological diversity. Most palm seeds lose viability quickly, and they cannot be preserved in low temperatures because the cold kills the embryo. Using botanical gardens for conservation also presents problems, since they can rarely house more than a few plants of any species or truly imitate the natural setting.Also, the risk of cross-pollination can lead to hybrid species.
The Palm Specialist Group of the World Conservation Union (IUCN) began in 1984, and has performed a series of three studies to find basic information on the status of palms in the wild, use of wild palms, and palms under cultivation. Two projects on palm conservation and use supported by the World Wildlife Fund took place from 1985 to 1990 and 1986–1991, in the American tropics and southeast Asia, respectively. Both studies produced copious new data and publications on palms. Preparation of a global action plan for palm conservation began in 1991, supported by the IUCN, and was published in 1996.
The rarest palm known is Hyophorbe amaricaulis . The only living individual remains at the Botanic Gardens of Curepipe in Mauritius.
Pests that attack a variety of species of palms include:
The palm branch was a symbol of triumph and victory in classical antiquity. The Romans rewarded champions of the games and celebrated military successes with palm branches. Early Christians used the palm branch to symbolize the victory of the faithful over enemies of the soul, as in the Palm Sunday festival celebrating the triumphal entry of Jesus Christ into Jerusalem. In Judaism, the palm represents peace and plenty, and is one of the Four Species of Sukkot; the palm may also symbolize the Tree of Life in Kabbalah.
The canopies of the Rathayatra carts which carry the deities of Krishna and his family members in the cart festival of Jagganath Puri in India are marked with the emblem of a palm tree. Specifically it is the symbol of Krishna's brother, Baladeva.[ citation needed ]
Today, the palm, especially the coconut palm, remains a symbol of the tropical island paradise.Palms appear on the flags and seals of several places where they are native, including those of Haiti, Guam, Saudi Arabia, Florida, and South Carolina.
Some species commonly called palms, though they are not true palms, include:
Rattan, also spelled ratan, is the name for roughly 600 species of Old World climbing palms belonging to subfamily Calamoideae. The greatest diversity of rattan palm species and genera are in the closed-canopy old-growth tropical forests of Southeast Asia, though they can also be found in other parts of tropical Asia and Africa. Most rattan palms are ecologically considered lianas due to their climbing habits, unlike other palm species. Though a few species also have tree-like or shrub-like habits.
Areca catechu is a species of palm which grows in much of the tropical Pacific, Asia, and parts of east Africa. The palm is believed to have originated in the Philippines, but is widespread in cultivation and is considered naturalized in southern China, Taiwan, India, Bangladesh, the Maldives, Sri Lanka, Cambodia, Laos, Thailand, Vietnam, Malaysia, Indonesia, New Guinea, many of the islands in the Pacific Ocean, and also in the West Indies.
Bactris is a genus of spiny palms which are native to Mexico, South and Central America and the Caribbean. Most species are small trees about 2 m tall, but some are large trees while others are shrubs with subterranean stems. They have simple or pinnately compound leaves and yellow, orange, red or purple-black fruit. The genus is most closely related to several other spiny palms—Acrocomia, Aiphanes, Astrocaryum and Desmoncus. The fruit of several species is edible, most notably B. gasipaes, while others are used medicinally or for construction.
Aiphanes is a genus of spiny palms which is native to tropical regions of South and Central America and the Caribbean. There are about 26 species in the genus, ranging in size from understorey shrubs with subterranean stems to subcanopy trees as tall as 20 metres (66 ft). Most have pinnately compound leaves ; one species has entire leaves. Stems, leaves and sometimes even the fruit are covered with spines. Plants flower repeatedly over the course of their lifespan and have separate male and female flowers, although these are borne together on the same inflorescence. Although records of pollinators are limited, most species appear to be pollinated by insects. The fruit are eaten by several birds and mammals, including at least two species of amazon parrots.
Roystonea is a genus of eleven species of monoecious palms, native to the Caribbean Islands, and the adjacent coasts of the United States (Florida), Central America and northern South America. Commonly known as the royal palms, the genus was named after Roy Stone, a U.S. Army engineer. It contains some of the most recognizable and commonly cultivated palms in tropical and subtropical regions.
Coccothrinax is a genus of palms in the family Arecaceae. There are more than 50 species described in the genus, plus many synonyms and subspecies. A new species was described as recently as 2017. Many Coccothrinax produce thatch. In Spanish-speaking countries, guano is a common name applied to Coccothrinax palms. The species are native throughout the Caribbean, the Bahamas, extreme southern Florida and southeastern Mexico, but most of the species are known only from Cuba.
Zombia antillarum, commonly known as the zombie palm, is a species of palm tree and the only member of the genus Zombia. It is endemic to the island of Hispaniola in the Greater Antilles. Usually found in dry, hilly areas of northern and southern Haiti and the northwest of the Dominican Republic, Z. antillarum is a relatively short fan palm with clustered stems and a very distinctive appearance caused by its persistent spiny leaf sheaths. Threatened by habitat destruction in Haiti, Z. antillarum is a popular ornamental species due to its distinctive appearance, low maintenance requirements and salt tolerance.
Attalea is a large genus of palms native to Mexico, the Caribbean, Central and South America. This pinnately leaved, non-spiny genus includes both small palms lacking an aboveground stem and large trees. The genus has a complicated taxonomic history, and has often been split into four or five genera based on differences in the male flowers. Since the genera can only be distinguished on the basis of their male flowers, the existence of intermediate flower types and the existence of hybrids between different genera has been used as an argument for keeping them all in the same genus. This has been supported by recent molecular phylogenies.
Chelyocarpus is a genus of small to medium-sized fan palms which are native to northwestern South America. Some are upright trees, while others creep along the ground. Species are used for thatch, to weave hats, stuff pillows and as a source of salt.
Cryosophila is a genus of medium-sized fan palms that range from central Mexico to northern Colombia. Species in the genus can be readily distinguished from related genera by their distinctive downward-pointing spines on the stem, which are actually modified roots. They are known as the "root spine palms".
Ravenea musicalis, or the river palm, is a species of flowering plant in the family Arecaceae. Also known by the Antanosy word "torendriky," meaning "submerged trunk", R. musicalis is known for being the only truly aquatic palm tree. Like many mangrove trees, R. musicalis seeds germinate within the fruit, and the seedling takes root underwater. Endemic to Madagascar, R. musicalis was first discovered in 1993 by Henk Beentje on an expedition funded by the McDonald's restaurant. This palm is listed in the IUCN Red List. This tree is harvested by local people primarily for building material and food. Over-harvesting, habitat degradation and habitat loss threaten the remaining populations. Horticulturalists prize R. musicalis for its rarity and unique life history.
Voanioala gerardii, commonly known as the forest coconut, is a species of flowering plant in the family Arecaceae. It is a relative of the coconut, and is generally regarded as monotypic within the genus Voanioala. However, a team of geneticists headed by Bee F. Gunn found sufficient genetic variation within Voanioala to constitute at least two and possibly four cryptospecies. Voanioala is endemic to Madagascar, and is threatened by habitat loss. Voanioala is harvested for its edible seeds and palm heart. It is estimated that there are fewer than fifteen mature trees remaining.
Roystonea regia, commonly known as the Cuban royal palm or Florida royal palm, is a species of palm that is native to Mexico, parts of Central America and the Caribbean, and southern Florida. A large and attractive palm, it has been planted throughout the tropics and subtropics as an ornamental tree. Although it is sometimes called R. elata, the conserved name R. regia is now the correct name for the species. The royal palm reaches heights from 50 to over 80 feet tall. Populations in Cuba and Florida were long seen as separate species, but are now considered to belong to a single species.
Roystonea borinquena, commonly called the Puerto Rico royal palm, is a species of palm which is native to Hispaniola, Puerto Rico and the Virgin Islands.
Cryosophileae is a tribe of palms in the subfamily Coryphoideae. The tribe ranges from southern South America, through Central America, into Mexico and the Caribbean. It includes New World genera formerly included in the tribe Thrinacinae, which was split after molecular phylogenetic studies showed that Old World and New World members of the tribe were not closely related.
Nypa fruticans, commonly known as the nipa palm or mangrove palm, is a species of palm native to the coastlines and estuarine habitats of the Indian and Pacific Oceans. It is the only palm considered adapted to the mangrove biome. This species is the only member of the genus Nypa and the subfamily Nypoideae, forming monotypic taxa.
Climbing palms are genera in the family Arecaceae that grow as lianas. "Initially erect, the slender stems seek out trees for support and climb up into the forest canopy by means of recurved hooks and spines growing on the stem, leaves and inflorescences. In all climbing palms the leaves are pinnate and grow along the stem instead of forming a dense crown. The stems of climbing palms, more often referred to as canes, are solid in contrast to bamboo poles which are almost always hollow." "The majority of climbing palms are also clumping palms [and sympodial], sending out new shoots from [below ground as suckers]." "About 600 species of palms in  genera have a climbing growth habit. Most noteworthy is the genus Calamus--the largest genus in the palm family with approximately 350 described species--source of nearly all commercial rattan."
Borasseae is a tribe in the palm subfamily Coryphoideae. The tribe ranges from southern Africa and Madagascar north through the Arabian Peninsula to India, Indochina, Indonesia and New Guinea. Several genera are restricted to islands in the Indian Ocean. The two largest genera, Hyphaene and Borassus, are also the most widespread.
Chuniophoeniceae is a tribe of palms in subfamily Coryphoideae of plant family Arecaceae. The four genera within the tribe are morphologically dissimilar and do not have overlapping distributions. Three of the genera are monotypic, while the fourth genus (Chuniophoenix) has three species.
Trachycarpeae is a tribe of palms in subfamily Coryphoideae of the plant family Arecaceae. It has the widest distribution of any tribe in Coryphoideae and is found on all continents, though the greatest concentration of species is in Southeast Asia. Trachycarpeae includes palms from both tropical and subtropical zones; the northernmost naturally-occurring palm is a member of this tribe. Several genera can be found in cultivation in temperate areas, for example species of Trachycarpus, Chamaerops, Rhapidophyllum and Washingtonia.
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