Let’s try to answer one of the big questions we ask ourselves when thinking about palm trees: Are they really trees?
Unlike in most other languages, in English they are usually called directly palm trees. But, as in any semantic debate, we must bear in mind that we will be walking on eggshells. The answer will basically depend on the definition we give to the word “tree”. In any case, let the fight begin!
Most dictionaries define a tree as “a woody perennial plant, typically having a single stem or trunk growing to a considerable height and bearing lateral branches at some distance from the ground.” (Oxford Dictionary) There is no doubt that a palms are plants, and in fact they are often quite tall. So far, we might think that palm trees fit the definition of a tree. There are, however, two other basic criteria that define the tree: first, its woody stem, and second, that they ramify at a certain height. Below we will carefully analyze both criteria to see if indeed palm trees are trees.
Do palm trees have a woody stem?
There is no shadow of a doubt that palms have a tall and columnar stem, which can reach tens of meters. What is not so clear is whether it is made of wood or not. In fact this is a difficult question to answer and again it depends on what we consider as wood. It is often argued that the stem of palm trees is not woody, since palm trees do not have a cambium (the tissue responsible for the secondary growth of classical trees). In plainer words, it is often thought that a characteristic of trees is that their trunks grow in width throughout their lives, while the stems of palms certainly do not have that capacity. Unlike (all other) trees, palms are not Dicotyledons, but are grouped in the Monocot group toghether with grasses, cereals, and bamboos, all plants without such secondary growth. However, this is an argument taken with a pinch of salt: It is true that the stems of some palm trees, such as Copernicia alba, have a high density and are considered timber used in carpentry. It is also true that the stems of palm trees are lignified (contain lignin fibers). Therefore, it cannot be ruled out outright that palm trees are a “high, woody-stemmed plant.”
Do palm trees branch at a certain height?
This is actually the strongest argument for concluding that palm trees are not trees. We have discussed erlier the different growth forms of plants, focusing on secondary growth (stem growing in width). There is another characteristic that makes the growth of palm trees unique. And it is that the vast majority of palm trees have a single meristem (or group of cells responsible for growth in height) at the tip of each stem. Multi-stemmed palms, which form several stems from ground level, can have several of these meristems, but single-stemmed palms only have one, and if we rip off the bud of growing leaves the palm will simply not be able to continue growing, and therefore both will end up dying after a few months. Although, like all rules, there are exceptions (for example, in the case of the African palm trees of the Hyphaene genus shown in the photograph), we can affirm that as a rule, palm trees DO NOT “branch at a certain height from the ground”.
palms undoubtedly have tree-like features, such as the fact that they are plants with a tall stem, others features are more open to discussion, such as the quality of having wood, and finally some do not fit the dictionary definition of a tree, such as the fact that their trunk is ramified into branches. But even in the latter case there are exceptional cases. Hence, while palms do not fit perfectly into the definition of a tree, it is very difficult to prove unequivocally that palms like Hyphaene are not trees. The debate remains open, clearly stuck in the grays of semantics, although biologically palms are Monocots and (the rest of) the trees are not.