• Indeed, it simply is not a phylogenetic categorization but a physio-ecological one. Tree, like shrub, liana, herbaceous, woody/non-woody are all terms solely used to place plants into functional groups based on how they grow. None of these has to do with their taxonomy.

    So the question is, what is a tree and is having secondary growth necessary to be one? Because monocots, like palms are, don’t have secondary growth, they use some workarounds. But why should that matter in the definition of a tree? I don’t know. So yeah, a coconut palm should be considered a tree. But it hasn’t got to do with phylogenetics (like explained in the article you linked).

    Also, millennia ago there have been vast forests of lycopods!! Just imagine huge trees that are actually spikemosses. So why shouldn’t a palm not be a tree?

    • my definition of a tree is basically “a plant consisting of a single pillar-like robust trunk”.

      most plants can be trees, especially ones that generally grow as bushes, if they are prodded into doing so by pruning and whatever other pressures, and there are some plants that seem to flip a coin to decide whether they grow into bushes or trees.