Palms hold plant records for the biggest seed, leaf and flower cluster
The coco de mer grows seeds weighing up to 30 kg. Raffia palms unfurl leaves 25 metres long, Corypha palms raise flower spikes holding millions of blossoms, and Colombia's wax palm reaches 60 metres. Palm trunks barely thicken with age, and they store unusual amounts of water.
Arecaceae, the palm family, counts about 2,600 species in 181 genera, mostly tropical and subtropical. They grow as climbers, shrubs, stemless tufts and the familiar trees, usually topped by a crown of large, evergreen compound leaves on a single unbranched stem; Hyphaene is the rare genus with branching trunks. Leaves are either fan-shaped or feather-shaped. Flowers are small, often white, arranged on a spike wrapped by bracts that harden to wood, and most fruits are single-seeded drupes.
The family name comes from areca, which reached New Latin through Portuguese from a Malayalam word for the areca nut. Palm derives from Latin palma, the flat of the hand, after the splayed leaf. Some palms grow as a lone shoot, like Washingtonia and Roystonea; others, including many rattans and Rhapis, form clumps by sprouting new shoots from buds near the base.
Anatomy explains their look. As monocots, palms lack the cambium that lets other trees add rings, so trunks stay roughly the same width from bottom to top, although some achieve a so-called anomalous thickening. Their stems are packed with living, water-rich tissue, far more than in broadleaf trees, which buffers them against drought and lets them keep transpiring in dry soil. The climbing Calamus can reach 200 metres in length.
Diversity peaks in wet lowland forests of South America, the Caribbean, the South Pacific and southern Asia, and Colombia may host more species than any other country. A few tolerate deserts in Arabia and northwestern Mexico. Only about 130 species live wholly outside the tropics; Chamaerops humilis reaches 44 degrees north in Liguria, and the nikau reaches 44 degrees south on the Chatham Islands. Long central to life in the Middle East and North Africa, palms supplied food and symbolised victory, peace and fertility.
Source: Arecaceae
