page:  = <unk> ( palm ) = 
   
   <unk> 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 a recent molecular phylogeny . 
   Somewhere between 29 and 67 species are recognised in the genus , with estimates of as many as 100 . Incomplete herbarium collections make it difficult to determine whether certain groups represent single species , or groups of similar species . <unk> species have a long history of human use , and include economically important sources of palm oil and fibre . Many species are fire tolerant and thrive in disturbed habitats . Their seeds are animal dispersed , including some which are thought to have been adapted for dispersal by now @-@ extinct Pleistocene megafauna . 
   
   = = Description = = 
   
   The genus <unk> has pinnately compound leaves — rows of leaflets emerge on either side of the axis of the leaf in a feather @-@ like or fern @-@ like pattern . Species are also non @-@ spiny palms and includes both large trees with stout stems up to 30 metres ( 98 ft ) tall and acaulescent palms ( one which lack an aboveground stem ) . The number of leaves per individual varies from about three to thirty @-@ five ; larger plants tend to have more and longer leaves . 
   Inflorescences are large , branched and borne among the leaves . The inflorescence consists of a main axis — the peduncle and the rachis — and a series of smaller branches , the <unk> . The <unk> , which bear the flowers , emerge from the rachis . The peduncle is the main stalk , connecting the rachis with the stem . Inflorescences either consist entirely of male flowers , or are predominantly female with a few male flowers . Fruit usually have two or three seeds , although fewer or more are present in some species , and are usually brown , yellow , orange @-@ brown or purple when mature . 
   Four different types of male flowers exist . On the basis of these flower types , the genus has often been split into four genera — a more narrowly defined <unk> , <unk> , <unk> and <unk> . The species sometimes referred to <unk> have coiled anthers , while the other groups have straight ones . The petals of those placed in <unk> are much shorter than the stamens , while those placed in <unk> and a more narrowly defined <unk> have petals that are longer than the stamens . Five species do not fit easily into any of these groups ; this fact has been used as an argument in favour of considering this group a single genus . 
   
   = = Taxonomy = = 
   
   <unk> has been placed in the subfamily Arecoideae , the tribe <unk> and the subtribe <unk> , together with the genera <unk> , <unk> , <unk> , Cocos , <unk> , <unk> , <unk> , <unk> , <unk> and <unk> . Within this subtribe , <unk> has been found to be a monophyletic group , and sister to the clade containing <unk> , <unk> , <unk> , <unk> and <unk> . 
   Disagreement exists as to whether <unk> should be considered a single genus , or a group of related genera . In their 1996 Field Guide to the Palms of the Americas , Andrew Henderson , Gloria Galeano and Rodrigo Bernal combined all the species in the subtribe <unk> ( as it was then defined ) into a single genus , <unk> . In his 1999 Taxonomic Treatment of Palm Subtribe <unk> , American botanist Sidney F. Glassman divided the group into five genera — a more narrowly defined <unk> , <unk> , <unk> , <unk> and <unk> . <unk> <unk> and John Dransfield recognised a single genus in their 2005 World Checklist of Palms , and Jean @-@ Christophe <unk> continued this usage in his 2008 review of the genus . 
   The multi @-@ genus approach is based solely on the structure of the male flowers ; no other characters could be consistently associated with one genus or another . Four of the genera — <unk> ( in a narrow sense ) , <unk> , <unk> and <unk> — correspond to four different types of male flowers found within the genus . However , a few species have flowers that are intermediate between these four types , including A. <unk> ( which Glassman placed in its own genus , <unk> ) and this has been used as an argument for the single @-@ genus approach . In addition , there are several hybrids between species that would be considered different genera under Glassman 's five @-@ genus system , which has also been used as an argument for placing them in a single genus . In 2009 Alan <unk> and colleagues published a molecular phylogeny of the subtribe which found that some species placed in <unk> were actually more closely related to species placed in <unk> than they were to other members of that genus ( if the five @-@ genus approach was used ) , while A. <unk> , placed in <unk> by Glassman , was actually a sister to both <unk> and <unk> . 
   
   = = = History = = = 
   
   The genus <unk> was first described Carl Sigismund Kunth in 1816 based on specimens collected by Alexander von Humboldt and Aimé Bonpland , although older , pre @-@ Linnaean descriptions exist , including Charles Plumier 's 1703 description of A. <unk> . The genus was named for Attalus III <unk> , king of Pergamon , known for his interest in medicinal plants . The type species is A. <unk> , a Colombian endemic . The genera <unk> and <unk> were described by Carl Friedrich Philipp von Martius in 1826 and 1837 respectively . <unk> was described by Hermann Karsten in 1857 , and <unk> by Orator F. Cook in 1942 . 
   
   = = = Species = = = 
   
   Experts disagree about the number of species in the genus <unk> ( broadly defined ) . In 1965 , Dutch taxonomist Jan Gerard Wessels Boer estimated that there may be as many as 100 species in the genus . In their 1996 Field Guide to the Palms of the Americas Andrew Henderson and coauthors recognised 29 species in the genus , while Sidney Glassman recognised 65 species in his 1999 treatment of the group . Largely following Glassman 's lead , <unk> <unk> and John Dransfield recognised 67 species in their 2005 World Checklist of Palms . An important element of this disagreement is the decision by Glassman to define species more narrowly than Henderson . As a result , what Henderson interpreted as variation within species , Glassman took as differences between morphologically similar species . This problem is complicated by the fact that many of these species are poorly represented in herbarium collections . The large size of the leaves , inflorescences and fruit of many <unk> species makes them difficult to collect . In addition , many important collections , including type specimen , have been lost or destroyed . Sparse or incomplete collections make it difficult to differentiate variation within a single species from variation between different species . 
   The three recent treatments ( Henderson and coauthors , Glassman , and <unk> and Dransfield ) recognised a total of 73 species , but only 20 species are accepted by all of them . The remainder account for either nine species or more than 40 . For example , what Andrew Henderson considered a single species , <unk> <unk> , other authors have considered a species complex consisting of four or five species . Glassman doubted the validity of A. <unk> as a species , and described four new species from material that had previously been attributed to A. <unk> — A. <unk> , A. <unk> , A. <unk> and A. <unk> . <unk> and Dransfield accepted both Glassman 's four species and A. <unk> . However , Jean @-@ Christophe <unk> was of the opinion that A. <unk> , A. <unk> and A. <unk> were all very similar , and thought it likely that they all represented the same species . 
   Another species complex in <unk> includes A. speciosa and related species . Henderson ( 1995 ) recognised A. speciosa and A. spectabilis , considering the latter to either be an acaulescent form of A. speciosa or a hybrid between it and A. microcarpa . <unk> and Dransfield accepted A. spectabilis , but Glassman considered it a dubious taxon . <unk> <unk> was recognised as a distinct species by Michael <unk> and coauthors ; Glassman and <unk> and Dransfield concurred , but Henderson considered it part of A. speciosa . Glassman also described a fourth member of this group , A. <unk> , and it is accepted by <unk> and Dransfield . 
   
   = = Reproduction and growth = = 
   
   <unk> species are monoecious — male and female flowers are separate , but are borne by the same plant . Various species have been described as being insect @-@ pollinated , including A. <unk> , while pollination in A. <unk> and A. speciosa , has been attributed both to insects and wind . 
   Seed germination is remote tubular — during germination , as the cotyledon expands it pushes the young shoot away from the seed . After germination , the stem initially grows downward before turning to grow upward and produce the aboveground stem . This produces a " saxophone shaped " <unk> portion of the stem . The fact that the shoot tips of <unk> seedlings are underground it likely to contribute to their fire @-@ tolerance . 
   
   = = Distribution = = 
   
   Species range across the Neotropics from Mexico in the north to Bolivia , Paraguay , and southern Brazil in the south . According to <unk> and coauthors , three species are found in Mexico , four in Central America , and 62 in South America . Three species are present in the Caribbean — two in Trinidad and Tobago , along the southern edge of the region , and one in Haiti . 
   
   = = Habitat and ecology = = 
   
   <unk> includes both large trees and small acaulescent palms which occupy a number of different ecological niches . Dense stands of some of the larger species are conspicuous elements on the landscape , while smaller species are found in both in the forest understorey and in savannas . 
   Disturbance has been implicated in the formation of vegetation dominated by large <unk> species . In seasonally dry Amazonian forests the density of large adult A. <unk> palms was correlated with canopy openness ; the species also dominates savannas formed by repeated forest fires in Trinidad and Tobago . <unk> speciosa forms pure stands in many parts of Brazil where natural forest vegetation has been cleared . Similarly , stands of A. <unk> in Bahia , Brazil ( which are cultivated for <unk> fibre ) are managed using fire — the seedlings survive cutting and burning , and are able to dominate burned forest patches . 
   The fruit are dispersed by animals ; fruit which are not dispersed frequently suffer seed predation by <unk> beetles . Certain species of <unk> have been mentioned as examples of " anachronistic " species which are adapted for dispersal by now @-@ extinct Pleistocene megafauna . On <unk> Island , <unk> , in the Brazilian Amazon , <unk> <unk> fruit were consumed by tapirs , collared peccaries , deer and primates . Rodents , including agoutis , fed upon the fruit and , as the fruit availability declined , they fed on the seeds . Other dispersers of <unk> fruit include Crested <unk> which consume the fruit and disperse the seeds of A. <unk> in the Brazilian Pantanal . 
   
   = = Uses = = 
   
   <unk> species have a long history of human utilisation . <unk> <unk> <unk> seeds have been found in archaeological sites in Colombia dating back to 9000 BP . A variety of species remain important sources of edible oil , thatch , edible seeds and fibre . The leaves of <unk> <unk> and A. <unk> are used extensively for thatching . Several species are oil palms , with A. speciosa among the most important economically . Products extracted from A. speciosa were reported to support over 300 @,@ 000 households in the Brazilian state of Maranhão in 2005 , and in 1985 it was estimated to support over 450 @,@ 000 households throughout the Brazil . <unk> fibres , extracted from the leaf bases of A. <unk> , are commercially important , and generated about US $ 20 million in annual income to Brazilian farmers in 1996 . 
   
   