Branches brown dry and woody

Sorry no pics at mo will upload later, I had a plant start of life deformed so I threw it in a small pot and let it be. After a while it started growing fine, I should of repotted into a bigger pot but I didn't. Anyways today I've discovered on a few branches about halfway up there is patches roughly 1 inch where it's gone brown dry and woody? The plant still looks alright and the branches are still green before and after this dying looking patches. Anyone seen this before and know what's up?

Weed is basically a woody plant by nature
I think it is more common in some strains
Best I can offer without a pic

Here's a pic

Normal