What, if anything, is a tree?

Georgia Ray explains that lumping every upright, long-lived, woody plant into one category makes about as much sense, in its basic biology, as doing the same with every sea creature. Yet there is a practical sense in which trees are what we climb and clear and plant for shade, and sea creatures are what we raise in fishing nets, so it is quite natural that our language provides terse terms for those. This post’s title copies that of Stephen Gould’s famous essay on phylogeny.

It turns out that corpse flowers (Rafflesia arnoldii) are aptly named. They are botanical zombies, parasites that have lost their chloroplasts, taking not just sustenance from their hosts, but also picking up some host genes every once in a while.

Botany is weird.