Bulbs. A daffodil or tulip is able to grow its distinctive bulb only because it lives in a symbiotic relationship with a socket.
Eupatorium. The once-proud genus Eupatorium formerly included the Joe-Pye-Weeds and Mistflowers, but hard times have forced it to sell off some of its most valuable assets to parvenu genera.
Gray, Asa. Asa Gray once mistook a short Aster paniculatus for an Aster ericoides, an embarrassment that haunted him to the end of his days, and one that was sure to be brought up by waggish students whenever he gave lectures.
Helianthus tuberosus. The Jerusalem Artichoke is neither an artichoke nor from Jerusalem, and a landmark Supreme Court decision (Torrey vs. Heliantheae et al.) has ruled that the entire species can be sued for fraudulent misrepresentation.
Photosynthesis. Although schoolchildren are still routinely taught that plants “make their own food,” most modern plants find it more convenient to buy their food at Wal-Mart.
Taraxacum. It has been estimated that the common dandelion (Taraxacum officinale) is more intelligent than the entire United States Congress collectively, although (curiously enough) not individually.