What happens to the leaf projections at the shoot tips of trees?
They may: • develop into full-sized leaves at once, by continued cell division, expansion and specialisation; • grow a little and then remain within a bud for a time, and then expand rapidly when the bud flushes later on; • become a small bud scale around an inactive bud; or • never get much bigger, and soon fall off. What about the shape of leaves? This varies greatly between different species, to some extent from one tree to another of the same species, and even within a single tree. For example, leaves may have: • stalks that are long, short or absent altogether; • blades which are divided up into separate leaflets, or not; • margins that are deeply lobed, finely toothed, wavy or uncut; • surfaces which are flat or undulating, hairy or smooth; and • texture that is tough and hard, or thin and delicate. Many features of leaf shape are useful in identifying one tree species from another. How big can leaves get? Their final length can vary between a few millimetres (for instance in Cas
