Possible Clues:

• One seeing (eg, crime)
• Tautological observer?
• It's seen running round tree by one on the spot
• Tree: it's seen flourishing all round - by me?
• The Observer forged new ties? Yes
• One who sees what happens
• One whose pupils are trained to take in events
• Spectator
• One sent up into English woods as spectator
• 1956 British thriller film starring Donald Sinden