Mystery Micrograph #07

Alright, this one should be a little bit easier.

To be referenced later; scalebar = 2um

Good luck!

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HINT (29.10.09):


(Source: Keeling et al 2005 TrEE; do I even need to keep citing this anymore? Can we be on familiar terms and refer to it as 'that tree' yet? =P )

It's somewhere in there... I'm so helpful it hurts, I know. Mwahaha.