Appearance
The purple, non-fragrant, invasive flowers of the ""Phaseolus giganteus"" are said to have snail or snail-shell shaped flowers, hence the origin of the common name. The multicolored, fragrant, non-invasive flowers of the "Cochliasanthus caracalla" are said to have corkscrew or nautilus-shell shaped flowers, hence the origin of that common name. Though some claim that the leaves of one species are darker and differently sized compared to the leaves of the other, it is difficult to distinguish between these two plants through foliage alone.There have been multiple instances where both plants have been grown side by side for years and the discovery that they were not the same species was made only after the less mature plant finally bloomed. It is said that both plants are pollinated by ants so, without ants, the plant will produce few, if any, seeds, although "C. caracalla" is pollinated by bees in Argentine, which is its native range.
Naming
The species is named "caracalla", a corruption of the Portuguese caracol, meaning snail."." Thomas Jefferson called this plant "the most beautiful bean in the world".References:
Some text fragments are auto parsed from Wikipedia.
