All About Palm Trees: a Photographic and Botanical Appreciation
I studied Life Sciences at college in the UK but graduated without ever learning anything about palm trees. I worked in the conservation of ancient woodlands on the outskirts of London for several years and still learned nothing about palm trees!
It is only since becoming a regular visitor to Southeast Asia that I have had the opportunity of photographing and studying these wonderful trees.
So, here is all I have learned about palm trees after visiting the beaches, forests, islands, estuaries and farmlands of South East Asia.
What Makes a Palm Tree, a Palm Tree?
Palm trees are angiosperms, which means flowering plants. They are monocots which means their seeds produce a single, leaf-like cotyledon when they sprout. This makes palms closely related to grasses and bamboos.
Palms can grow very fast. A Fish Tail Palm can grow to 10 meters (thirty feet) in as little as six years when conditions are optimal.
One reason that palms grow fast is that they invest less energy in defending themselves against insect damage than deciduous trees. They can still have tough outer layers, though, and some have dense 'woody' trunks.
Are Palms Really Trees?
Many botanists refuse to see palm trees as true trees because they lack the characteristics of secondary growth.
Secondary growth simply means the steady outward growth of a deciduous tree trunk or branch which gives rise to annual tree rings.
Any gardener is happy to call a tall palm, a tree, but some palms are not even remotely tree-like. Some fit the definition of shrub much better. Some, like Rattan species climb like lianas.
Where did Palm Trees Come From?
Palms are one of the most successful early monocots.
They appeared around 80 million years ago and spread right across the world. Competition from more modern trees has eliminated palms from many of the niches that they once occupied but they are still common in warmer climates.
This early arrival, in evolutionary terms, has given palm trees plenty of time to develop very complex lifestyles. The reproductive strategies of palms often include close relationships with particular kinds of insects, some of which are described below,
Palms also developed into very large trees and are the biggest monocots that have ever been. The Wax Palm, common in the Andes, can stand 60 meters (two hundred feet) tall.
The Botanical Classification of Palm Trees:
Palm Tree Leaves
Palm leaves are evergreen and range from small to gigantic (check out the pictures below). The leaves are palmate, alternate or (in rare cases) spiral.
If you are trying to identify a palm tree, leaf shape is the first place to start.
Palms grow like grasses, with sheathes that wrap around the stems or trunks then give rise to a leaf.
The successive leaf sheaths are very noticeable, as you can see in the pictures below.
When a leaf dies, it leaves a distinctive band (called an excision band) behind.
Spines on stems, trunks and even leaves are sometimes present and deter grazing animals.
They can also be a nightmare for gardeners.
Palm Flowers and Fruits
Reproduction in palm trees is complicated. Usually, though, there are small male and female flowers, sometimes on the same individual (hermaphrodite) plant, more often on separate male and female plants.
The flowers are often tiny but the structures (rachillae) that bear the flowers are usually big and obvious. There are some pictures of rachillae below,
Some palms shed pollen that is blown to female plants in the wind. Most palms are pollinated by insects.
The majority of palm fruits are inedible but some palms bear important food crops like dates and coconuts.
An Example of Reproduction in Palm Trees
The photo below shows flowers and fruit in various stages of ripening.
The Bismarck Palm: Bismarckia nobilis
This palm is a big, showy shrub that is a favorite in parks and garden around the world.
Below is a series of photos showing some of the stages in reproduction and fruit formation.
The flowers in the picture above were surrounded by hundreds of tiny bees. I could see them with the naked eye, but I didn't manage to catch them on camera!
It is these kinds of creature that are so important for the pollination of the majority of palm trees.
Six Months for the Fruit to Ripen
The fruit of the Bismark Palm is not edible for humans, although a lot of fruit bats lived among the palms that I photographed. Were they eating the fruit or just sheltering beneath those broad cool leaves?
The ripening process is very slow and it takes at least six months before seeds can be taken and used to plant out.
Other Notable Ornamental Palms
Edible Palm Products
Dates have been cultivated in the Middle East for thousands of years and receive mention in the Bible. They probably originated in the regions around the Persian Gulf but are now grown in places as far away as China, Pakistan, Australia and the US.
The fruit has a high sugar content at around 60 per cent of dried weight but also numerous vitamins and trace elements.
Yields can be impressive in the right conditions. The variety 'Deglet Noor', growing in California can deliver up to 7 tons of dates per acre in a year!
They can be eaten as they are. or cooked in deserts, candy bars and even used in ice-creams.
Young date leaves can also be eaten and sap can be drawn from the trunk to produce a sugary liquid. This ferments into alcohol quickly.
Date palms require dry conditions and like heavy loam soils.
The scientific name of the date palm is Phoenix dactylifera.
Coconut Palm: Cocos nucifera
The Coconut Palm likes warm, humid conditions, sandy soil and can tolerate salt. Since the coconut floats and can survive in sea water for long periods it has been able to spread naturally across vast distances of ocean and is often found on tropical beaches.
Human beings, valuing the many products of the Coconut Palm, have also helped in its spread.
- Young coconuts are harvested for coconut milk, a tasty and nutritious liquid that is part of the food store (endosperm) of the seed.
- Older coconuts have a thick layer of solid endosperm called coconut meat. This is used in cooking and the production of many biscuits, deserts and candy bars. Oil can also be extracted for food and beauty products.
- The fibrous 'coir' has many uses including making mattresses, brushes and matting.
Coconuts have been around a long time. The oldest fossils date from 37 to 55 million years ago
Oil Palms can be huge, up to 60 feet (20 m) in height. They produce clusters of dark red fruit that mature in about six months from pollination. Each cluster can weigh as much as 120 lbs.
Both the seeds and the flesh of the fruit are rich in oil. Some is used in cooking, some in beauty products and a great deal is used as a biodiesel helping to power cars, ships and heating systems.
Oil palms are grown in huge numbers in South East Asia, often in areas that have been cleared of tropical rain forest. The damage to tropical environments has made this palm especially controversial.
Areca Palm- the 'Betel Nut Palm'
The fruit of the Areca palm has been collected, dried and chewed with betel leaves for thousands of year across Asia.
It has a mild stimulant effect and is used on certain ceremonial occasions. In Vietnam, for example, Betel Nut is chewed when parents of a potential bride and groom meet to discuss marriage arrangements.
Despite this, and similar customs across Asia, the habit of chewing Betel Nut is gradually dying out, mainly as a result of the arrival of coffee and cigarettes. It is usually only the older generation who still use the preparation.
Like cigarettes, Betel Nut is carcinogenic but is apparently less addictive.
Other Commercially Important Palms
- Ivory nuts
- Carnauba wax
- Rattan cane