[MiguelVieira]

I like David Allen Sibley's definition of a tree: "If you can walk under it, it's a tree; if you have to walk around it, it's a shrub".

[bee_rider]

But you still have to walk around trees, at least the trunk part. Maybe a tree is a subset of shrubs. Maybe shrubs are graphs.

[k_sze]

If a tree doesn’t topple after a millennium, it’s a…

[bee_rider]

Y2K compliant data structure

[hinkley]

force of nature.

[mcv]

I like that definition, but: is a tree with very low branches (like a fir) really a shrub? Does a fallen tree become a shrub?

[tshaddox]

And are walls, houses, rivers, people, etc. all shrubs?

[jameshart]

Christmas trees: actually Christmas shrubs.

[hinkley]

Christmas trees aren't just murdered trees, they're murdered baby trees.

[DeadMouseFive]

But what about plants that can be pruned to both shapes?

[agentwiggles]

Trubs, obviously

[jmull]

Shreebs.

[bagacrap]

Christmas Shrub then?

[euroderf]

Maybe Hanukkah Bush is a totally valid taxonomic classification.