Possible Clues:

• I will join accountants up a gum tree
• Plant doubly if little account comes up very well
• A CA is prickly over the CIA
• Account given to adult at intelligence agency for burning Bush possibly
• Pod-bearing tree
• Accountant spies flowering tree
• Gum source
• Twice Bill and I get stuck together touching a gum tree
• Yellow-flowered shrub
• Looking back, two accountants returning first class with floral emblem from down under