A strange looking drift seed we found on the beach is the hamburger bean. When we first found one on the beach we weren't sure if it was a drift seed or some sort of man-made object.
It turns out there are many varieties of hamburger beans. Our hamburger bean appears to be from the mucuna family. The mucuna is a species of climbing, woody vines that are found world-wide in tropical regions. We have no idea exactly what type of mucana it is, but our guess it is a mucuna urens.
Not knowing exactly what this drift seed will turn out to be, or how it may potentially impact the garden, we intend to plant it in a pot and see what happens.