Why are my leaves dissappearing and turning black So I have a leaf material with transparent alpha, and I used a particle system to put it on an empty tree to make it look like it has leaves. The texture I used had a transparent background so I used a transparent material to make it actually transparent.




But this is what happens when I convert the particle system and join it with the tree. It's so annoying, it's happened once before when I tried to use the array modifier to an image with a transparent background and the background turns black despite having the right material. What do I do? 

 

EDIT: 

I'm pretty sure it now has something to do with UVs because I unwrapped the leaves again and the leaves were messed up. Is there like a short way to do this? When I join the leaves and the tree the UV resets.
I ran into this issue as well.  I started with the tree sapling, then added the leaves - like you did with alpha - same thing - after converting and removing the particle system, then joining, the leaves would not show in rendered mode.

I noticed that the sapling was generated wit it's own UV Map - "Orco" - once I deleted that UV Map, the join worked as expected.

I was pulling my hair out for a good while, and I don't have much to work with.