Possible Clues:

• What a leafstalk leads to
• Leaf bisector
• Large vein on leaf
• Note winged creature crawling up part of leaf
• Note inversion of flying creature's major vein
• Most of 33 down on small boat see it turning over a new leaf perhaps
• Central leaf vein
• Socialise briefly serving up goose - you'd need to turn over a new leaf for that sort of gander
• Flier the setter's sent up in this vein?
• Leaves with one in the centre