Coconut palm on a sunny beach. Photo: http://www.elsetge.cat
I’ve long been a major fan of palms (palm trees), probably because I live in a climate far too cold for any palm to survive outdoors. So, to me, they are the ultimate sign of exoticism. I’ve been growing different species indoors (plus outdoors in the summer) since I was a child, many from seed.
But if you think palms are tall trees found only on tropical beaches, you’d be wrong. They’re widely distributed throughout tropical and subtropical regions of the world, living everywhere from rainforests to deserts, and indeed, some even grow in (mild) temperate climates. And their forms very widely.
Here are some facts about palms you probably didn’t know.
1. Palm trees aren’t trees. Botanically speaking, they are large, woody herbs. A true tree is woody with “secondary growth”: its stems thicken over time, in fact, considerably so. That’s why the thin stem of a sapling turns into a wide trunk as it puts on layer after layer of new wood. Palms are monocots (more closely related to grasses than oaks or maples). Their “trunks” are actually stems (called stipes) and have no rings nor true wood. Whatever width the stipe has as it forms, it will keep all its life. Of course, if you want to call a palm a palm tree, go right ahead. Even dictionaries do … but botanists, who know a lot more about palms than dictionary editors, certainly don’t.
2. Although the coconut palm (Cocos nucifera) is the classic image of a palm, there are over 2600 species in the palm family (Arecaceae). Many are treelike, with a single, upright growing stipe, others are shrubs, with only a short stipe or even no visible above-ground stipe and yet others are creeping or climbing plants. The rattan chairs we use in our gardens come from the stipes of climbing palms.
3. Palms don’t produce branches (or at least, hardly ever). Think of that classical coconut palm again: the trunk may bend, but never branches. There are a very few exceptions. A few species are dichotomous (their trunk splits in two parts) as they mature and, very rarely, if the apex is damaged, branching may occur on other palms, but most people even in tropical climates where palms are abundant have never seen a palm with branches. When you think of it, the plant’s single “trunk” is part of what helps most of us define a plant as being a palm! Many palms are said to be solitary, with a single stipe, but others do produce offsets at the base and are called clustering palms.
4. Palm branches are leaves. Again, there is a long tradition of “palm branches” in many societies. In Christian cultures, for example, Palm Sunday represents the entry of Jesus into Jerusalem and is symbolized by “palm branches.” The Romans rewarded champions of games with palm branches. In fact, those “branches” are leaves, better referred to as fronds.
5. Palm fronds come in two shapes … well, five actually. They are usually either pinnate (featherlike), with leaflets attached to a single leaf axis like a feather, or palmate (fan-shaped), rounder, with all the leaflets spreading out from the same point, like a hand. There is also a much rarer intermediate form, said to be costapalmate: partially palmate, and partially pinnate. You could see it as being an elongated palmate leaf. Some pinnate leaves are doubly pinnate or bipinnate: each leaflet is in itself featherlike. And then there are entire leaves, similar to pinnate leaves in their overall shape, but simple and undivided. They’re very rare. Palm fronds are almost always spirally arranged at the tip of the stem. Often, they are spiny, especially at the base.
6. Not all plants called palms are members of the palm family (Arecaceae). Among plants commonly referred to as palms, but that aren’t, are the cabbage palm (Cordyline australis, Asparagaceae), the Madagascar palm (Pachypodium lamerei, Apocynaceae), the sago palm (Cycas revoluta, Cycadaceae) and the traveler’s palm (Ravenala madagascariensis, Stretitziaceae). They’re just a few examples of plants whose common names suggests a relationship to true palms, but really have none.
7. There are “hardy palms.” They can take frost and snow … at least for short periods. The best known of these hardy palms is the Chinese windmill palm (Trachycarpus fortunei), which is sometimes grown as far north as Vancouver, Canada and southern Sweden. It’s said to be hardy to USDA hardiness zone 8 and has even been grown in zone 6b, but only under very special conditions.
8. The world’s tallest palm and, indeed, the world’s tallest monocot, is the Quindio wax palm (Ceroxylon quindiuense). It can reach up to 200 feet (60 m) in height. It grows in the humid montane forests of the Andes in Colombia and Peru.
9. The coconut palm (Cocos nucifera) is one of the most useful plants in the world. Besides charming tourists on sandy beaches, it provides food, oil, soaps, soft drinks, alcoholic beverages, clothing, shelter, potting mix, fiber and “wood” for construction. And that’s only a start! There is no part of the coconut palm that has not found a use.
10. The world’s largest and heaviest seed comes from a palm. The coco de mer or sea coconut (Lodoicea maldivica), from the Seychelles, has seeds can be as large as 20 inches (50 cm) in diameter and as heavy as 92 pounds (42 kg)! The seed takes 6 to 7 years to mature and a further two years to germinate.
Palms: fascinating, aren’t they?