This is another genus that is under study by
taxonomists. Therefore, the number of
species to include ranges from a low of
about 65 up to a high of over 300.
A
genus of many alternate leaved species of herbs
or climbing plants with simple leaves, numerous
small flowers (consisting only of a calyx and 5
sepals) in spikes, heads or racemes. Some
species may become invasive.
The name is Greek,
poly, meaning "many"
and gonu, meaning "knees".