The Palm Family is a tropical family, with some species in the subtropics and only a few in warm-temperate regions. There are about 200 genera and just under 3,000 species. Arecaceae 03 Tree habit 03-Roystonea regia Most palms have a single apical bud and are usually unbranched trees, as seen in the Royal palm, Roystonea regia. Remember that palms are monocots, so true wood is not produced Photo taken by K. R. Robertson in Panama. Arecaceae 04 Shrub habit 04-Serenoa repens habit The saw palmetto, Serenoa repens, is more of a shrub, with a aboveground, horizontal, branching stems. It occurs in South Carolina, Florida, Alabama, and Mississippi. Photo taken by K. R. Robertson in Florida. Arecaceae 05 Pinnate leaves 05-Pinnate leaves The leaves of most palms are pinnately compound, and some can be very large, up to 65 feet long! Photo taken by K. R. Robertson in Jamaica Arecaceae 06 Palmate leaves 06-Palmate leaves Some palms have palmately lobed or compound leaves, and some of these can be very large as well. Photo taken by K. R. Robertson in Jamaica. Arecaceae 07 Palm trunk 07-Palm trunk The trunks of palm trees are often covered with the remains of overlapping leaf bases, which add structural rigidity. The persistent petioles can sometimes act as spines. Photo taken by K. R. Robertson in the Climatron at the Missouri Botanical Garden Arecaceae 08 Palm inflorescences 08-Palm inflorescence Inflorescences in palms are diverse spikes or panicles. Most are produced laterally on the trunks. In this photo, male inflorescences are above the female ones. Nearly all palms have many flowers in an inflorescence. Photo taken by K. R. Robertson Arecaceae 09 Palm flowers 09-Palm flowers The flowers of palms are usually small and 3-merous. This example is Roystonea borinquena . Photo taken by K. R. Robertson in Jamaica Arecaceae 10 Coconut palm 10-Cocos nucifera habit One of the most familiar and widespread palms is the coconut, Cocos nucifera. Photo taken by K. R. Robertson in Jamaica. Arecaceae 11 Coconut flowers 11-Cocos nucifera flowers The flowers of coconuts are imperfect and the plants monoecious. Here you see male flowers above a few female flowers. Photo taken by K. R. Robertson in Jamaica. Arecaceae 12 Young coconut fruits 12-Cocos nucifera The fruits of coconuts are drupes; here you see young fruits developing. Photo taken by K. R. Robertson Arecaceae 13 Coconut Drupe 13-Cocos nucifera fruit This is a fresh coconut in longitudinal section (made with a machete!). The fruit of a coconut is a drupe, in which the mesocarp is fibrous. The "nut" you buy at the grocery store is the "pit", and the white stuff that you eat is the endosperm.
Coconut trees usually grow near the ocean, some of the ripe coconuts fall into the ocean (or are blown there by hurricanes), and then they are carried along on the ocean currents, where eventually at least some of them wash up some other tropical beach, where they germinate. Photo taken by K. R. Robertson in Jamaica. Arecaceae 14 Jelly Coconut 14-Cocos nucifera A great delicacy in the tropics is a "jelly" coconut. The top of an unripe, green coconut is chopped off with a machete, and one then drinks the coconut "milk" and eats the endosperm, which is jelly-like at this stage of development. Photo taken by K. R. Robertson Arecaceae 15 Double Coconut 15-Lodoicea maldivica The coco-de-mer or double coconut, Lodoicea maldivica, produces what is the world's largest seed. This species is restricted to the Seychelles island in the Indian Ocean. Arecaceae 16 Oil Palm 16-Oil palm The oil palm, Elaeis guineensis, is extensively grown in tropical countries. Two distinct oils come from this plant, one from the fruit pulp and another from the seed. Like the oil found in coconuts, palm oil is high in saturated fats, unusual for a vegetable oil. Arecaceae 17 Date Palm 17-Date palm trees Date palms, Phoenix dactylifera, are native to oases the Sahara Desert and have been cultivated for at least 4,500 years, first by the ancient Egyptians. Now, dates are widely cultivated in many hot, dry regions of the world. Date trees are dioecious, but as early as 2,300 B.C., agriculturists had learned to hang a male inflorescence in a female tree to enhance pollination, which is by wind. The date fruits are produced in great quantities. The fruits are very nutritious, containing over 60% carbohydrates and 5% protein. Arecaceae 18 Royal Palms 18-Roystonea regia The stately royal palm, Roystonea regia, is widely cultivated in tropical countries. Photo taken by K. R. Robertson of the U.S. headquarters in the Panama Canal Zone, back when the Zone was controlled by the U.S Arecaceae 19 Talipot Palm 19-Corypha The Talipot palm, Corypha umbraculifera, is monocarpic, living for many years then flowering, setting fruit, and then dying. This species can have 3㪧 million flowers, more than any other plant species, and up to 250,000 fruits. This photo is of a plant in fruit. Photo taken by K. R. Robertson at the USDA Plant Introduction Station in Coral Gables, Florida. Arecaceae 20 Washingtonia 20-Washingtonia filifera There are two species of the genus Washingtonia, which was named after George Washington. Both species are native to southwestern North America; this example is Washingtonia filifera. They are very large trees with palmately lobed leaves; they are often cultivated as street trees in suitable climates. Photo taken by K. R. Robertson on the island of Madeira.