Big Dripleaf's texture stretches when grown

The Big Dripleaf's texture stretches when grown. It's a little hard to understand without a video so I've attached one below.

What I expected to happen was...:
The texture would look the same.

What actually happened was...:
It stretched.

Steps to Reproduce:
1. Place a Big Dripleaf
2. Look closely at it's stem
3. Bone meal it

Note:
Is best seen with particles on minimal.