However, palms exhibit an enormous diversity in physical characteristics and inhabit nearly every type of habitat within their range, from rainforests to deserts.

In many historical cultures, because of their importance as food, palms were symbols for such ideas as victory, peace, and fertility.

Palm originates from Latin palma semantically overlapping with sense of "hand front" (due to similar splayed shape) ultimately from Proto-Indo-European *pl̥h₂meh₂, a direct descendant folm once existed in Old English.

[8] 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.

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.

[11] This explains the cylindrical shape of the trunk (almost constant diameter) that is often seen in palms, unlike in ring-forming trees.

Ceroxylon quindiuense, Colombia's national "tree", is the tallest monocot in the world, reaching up to 60 metres (197 ft) tall.

The Corypha species have the largest inflorescence of any plant, up to 7.5 metres (25 ft) tall and containing millions of small flowers.

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.

[14] In the southern hemisphere, the southernmost palm is the Rhopalostylis sapida, which reaches 44°S on the Chatham Islands where an oceanic climate prevails.

[17] 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.

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.

This has revealed, for example, that a whole-genome duplication event occurred early in the evolution of the Arecaceae lineage, that was not experienced by its sister clade, the Dasypogonaceae.

The Arecaceae were the first modern family of monocots to appear in the fossil record around 80 million years ago (Mya), during the late Cretaceous period.

[23] Several species of palms have been identified from flowers preserved in amber, including Palaeoraphe dominicana and Roystonea palaea.

Barreveld wrote:[29] 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.

[33] This is far higher than almost any other plant family, sixth out of domesticated crops in the human diet, and first in total economic value produced – sharing the top spot with the Poaceae and Fabaceae.

The greatest risk to palms is destruction of habitat, especially in the tropical forests, due to urbanization, wood-chipping, mining, and conversion to farmland.

[45] 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.

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.

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.

Preparation of a global action plan for palm conservation began in 1991, supported by the IUCN, and was published in 1996.

[citation needed] In 1840, the American geologist Edward Hitchcock (1793–1864) published the first tree-like paleontology chart in his Elementary Geology, with two separate trees of life for the plants and the animals.

[17] 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.