During the turn in which your bonsai matches or exceeds the requirements of a Goal tile that is still in the middle of the table (i.e., the Goal tile has not been claimed yet by any player), you must immediately choose whether you want to claim that tile or if you want to renounce it in order to try to achieve a harder Goal tile.
If you complete and claim a Goal tile, take the tile and keep it beside your bonsai. You may only claim one Goal tile per color. If you renounce taking a Goal tile when you complete it, you may still try, in subsequent turns, to complete a harder Goal tile of the same color, but you may no longer claim the one you renounced.
Example: At the start of her turn, Martha has a bonsai with 4 leaves. She adds 2, bringing the total to 6. Now she could claim the Goal tile showing 5 leaves which is worth 6 points, or she can renounce it and try to claim the one showing 9 leaves which is worth 12 points.
The intermediate tile, the one showing 7 leaves worth 9 points, was already claimed by Bryce so it cannot be taken anymore.