African Sherbro or Piassava comes from Sierra Leone in Western Africa. It grows as part of the leaf structure of the Bassa Palm, and is harvested by the traditional method of cutting the leaves from the trees and soaking until the outer husk begins to break down.
This process is called "retting", and the unwanted part is then combed away by hand, on bamboo hackles stuck into the ground.
This fibre is almost exclusively used for stiff yard or scavenger type brooms, where a very vigorous sweeping action is required, combined with hard-wearing properties. It was also used in mechanical road sweepers, but has more recently been superseded by either synthetic materials or steel filaments.
How it got the generic name of "Bass" as in "Bass broom" is unclear. Some believe it to have come from the Bassa Palm from which it originates. A more romantic version of the tale is that when the material was first traded in the late 1800's that merchants bartered bottles of Bass beer in exchange for the fibre.
This fibre has had a chequered history over the years. At one time it was extremely popular, especially when brooms of the scavenger type were hand made by a process called "hand setting". The tufts of fibre were set into pre-drilled holes by hand, having first been bound with a piece of thin hemp and dipped in molten pitch.
The fibre is still readily available, and we can of course fully dress Natural Sherbro, or mix it with other materials such as polypropylene to make it easier to work with.