Related Clues:

• Covering of tree trunk
• Animal sound — layer protecting tree trunk
• Certain traditional medicine source
• Outside of a tree
• Tree's protective layer
• Lab report?
• Source of cinnamon spice
• ''Arf'' or ''woof''
• Dog's greeting
• Heading for Bristol on one vessel or another
• Medium for love letters?
• Sound from a spaniel
• Source of cinnamon
• Shout gruffly; part of tree
• Prevent king seeing coverage of the Oaks?