You can find information about the Citrus Ball Cactus in this thread.

By the way, the easiest way to find something in the forums is to click the Advanced button under the search window at the left side of the forums and change the date range to a longer time (depending upon the game that you're looking for help with). For example, try typing "Citrus Ball Cactus" (with the quotation marks) in the Keyword Search Terms window, and change the date range to 3 months. You'll find lots of answers!