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The Arecaceae are a botanical family of perennial lianas, shrubs, and trees commonly known as palm trees. (Due to historical usage, the family is alternatively called Palmae or Palmaceae.[3]) They are flowering plants, the only family in the monocot order Arecales. Roughly 202 genera with around 2600 species are currently known, most of them restricted to tropical, subtropical, and warm temperate climates. Most palms are distinguished by their large, compound, evergreen leaves arranged at the top of an unbranched stem. However, many palms are exceptions, and in fact exhibit an enormous diversity in physical characteristics. As well as being morphologically diverse, palms also 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, and palms are also widely used in landscaping for their exotic appearance, making them one of the most economically important plants. In many historical cultures, palms were symbols for such ideas as victory, peace, and fertility. Today, palms remain a popular symbol for the tropics and vacations.[4]
Whether as shrubs, trees, 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.[5]
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.[6] 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)[7] but some genera (e.g. Salacca) may contain two or more seeds in each fruit.
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 meters tall.[8] The coco de mer (Lodoicea maldivica) has the largest seeds of any plant, 40–50 cm in diameter and weighing 15–30 kg each. 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 grow in the tropics. They are abundant throughout the tropics, and thrive in almost every habitat therein. Their diversity is highest in wet, lowland tropical forests, especially in ecological "hotspots" such as
Some species commonly called palms, though they are not true palms, include:
Today, the palm, especially the coconut palm, remains a symbol of the tropical island paradise.[11] 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.
Panaiveriyamman was an ancient Tamil tree deity related to fertility. Named after panai, the Tamil name for the Palmyra palm, she was also known as Taalavaasini, a name that further related her to all types of palms.[26]
The palm branch was a symbol of triumph and victory in pre-Christian times. 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 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.
Pests that attack a variety of species of palm trees include:
The rarest palm known is Hyophorbe amaricaulis. The only living individual remains at the Botanic Gardens of Curepipe in Mauritius.
The Palm Specialist Group of 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.[25]
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 only house a few plants of any species or truly imitate the natural setting.[25] Also, the risk of cross-pollination can lead to hybrid species.
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. 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.[24] The sale of seeds to nurseries and collectors is another threat, as the seeds of popular palms are sometimes harvested directly from the wild. At least 100 palm species are currently endangered, and 9 species have reportedly recently become extinct.[11]
The southeastern U.S. state of South Carolina is nicknamed the Palmetto State after the sabal palmetto (cabbage palmetto), logs from which were used to build the fort at Fort Moultrie. During the American Revolutionary War, they were invaluable to those defending the fort, because their spongy wood absorbed or deflected the British cannonballs.[22] The sabal palmetto is also the state tree of Florida. Some palms can be grown as far north as the United States' Mid-Atlantic, such as Washington D.C.'s National Arboretum, southern Midwest, and even north along the Pacific coast to Oregon, Washington and British Columbia, where ocean winds have a warming effect. Species of transplanted palms have even been known to have survived as far north as Devon. The Chinese Trachycarpus fortunei is being grown experimentally on the Faroe Islands at 62°N, with young plants doing well so far.[23]
Along with dates mentioned above, members of the palm family with human uses are numerous.
Arecaceae have great economic importance, including coconut products, oils, dates, palm syrup, ivory nuts, carnauba wax, rattan cane, raffia and palm wood.
An indication of the importance of palms in ancient times is that they are mentioned more than 30 times in the Bible,[20] and at least 22 times in the Quran.[21]
Human use of palms is as old or older than human civilization itself, starting with the cultivation of the date palm by Mesopotamians and other Middle Eastern peoples 5000 years or more ago.[18] Date wood, pits for storing dates, and other remains of the date palm have been found in Mesopotamian sites.[19] The date palm had a tremendous effect on the history of the Middle East. W.H. Barreveld wrote:
Evidence can also be found in samples of petrified palmwood.
The Arecaceae are the first modern family of monocots clearly represented in the fossil record. Palms first appear in the fossil record around 80 million years ago, during the late Cretaceous period. The first modern species, such as Nypa fruticans and Acrocomia aculeata, appeared 94 million years ago, confirmed by fossil Nypa pollen dated to 94 million years ago. Palms appear to have undergone an early period of adaptive radiation. By 60 million years ago, 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.[16] Several species of palms have been identified from flowers preserved in amber, including Palaeoraphe dominicana and Roystonea palaea.[17]
See list of Arecaceae genera arranged by taxonomic groups or by alphabetical order for a complete listing of genera.
[14] explored subfamily and tribe relationships using chloroplast et al. Currently, few extensive phylogenetic studies of Arecaceae exist. In 1997, Baker
[14] 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.monoecious) 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 Podococceae - Iriarteeae - Geonomeae - Cocoeae - Caryoteae - Areceae of three joined carpels. The Arecoideae are the largest subfamily, with six diverse tribes (gynoecium 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 [13] The Coryphoideae are the most diverse subfamily, and are a
A few general traits of each subfamily are listed. [12] Palms are a
Palms inhabit a variety of ecosystems. More than two-thirds of palm species live in tropical forests, where some species grow tall enough to form part of the canopy and shorter ones form part of the understory.[11] 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 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.[10]
Only an estimated 130 palm species grow naturally beyond the tropics, mostly in the subtropics. The northernmost native palm is Chamaerops humilis, which reaches 44°N latitude in southern France.[10] The southernmost palm is the Rhopalostylis sapida, which reaches 44°S on the Chatham Islands where an oceanic climate prevails.[10] Some palms, such as the Trachycarpus fortunei, grow well under cultivation in temperate climates, some as far north as 50°N in oceanic climates (Ireland, Scotland, England, and the Pacific Northwest, from Oregon to Vancouver).
[9]
Jurassic, Paleogene, Neogene, Cenozoic, Devonian
Manila, Metro Manila, Indonesia, Australia, Malaysia
Idaho, Columbia River, Portland, Oregon, Kansas, Montana
Philippines, Malaysia, Sugar, Solomon Islands, Madagascar
Quran, Old City (Jerusalem), State of Palestine, Islam, Jordan
Myrtaceae, Rutaceae, Rosaceae, Arecaceae, Annonaceae
Temperature, Arecaceae, Deep foundation, Rice, Bamboo
Arecaceae, Cyclanthaceae, Araceae, Pandanales, Pandanaceae
Gibraltar, Arecaceae, Politics of Gibraltar, Canary Islands, Africa
Florida, Cuba, Arecaceae, Mexico, Kolkata