There are also Mature Cotton Plant nodes, which are rare... I've seen 3 I think since live. These yield mature cotton from harvesting the same as a normal cotton node.
There is supposedly a very rare tier above Mature, but I haven't seen that yet. Plus I heard there are currently no recipies that use the very rare items.
Haven't seen Mature Firegrass either, although it is rumored to exist
I have gotten scraggy hide exactly once, I'm somewhere around 215 skinning skill.