whose yields rise dramatically if it can be kept off the ground, where it becomes affected by mildew.

• Winged bean—a climbing bean that could become a major crop of the tropics if cheap ways to support it can be found.

• The viny types of lima beans, common beans, common peas, and runner beans that tend to be the highest yielding varieties but are seldom grown because of the expense of staking them or the lack of poles.

• Beans, squash, or other climbing plants traditionally grown on maize. Switching to sorghum might extend this useful practice to locations too dry for maize.

Strictly speaking, this book is about plants that produce food, but we cannot resist rounding out the sorghum story with a glimpse at this plant's actual and potential utility as a source of everyday items for industry and for people in their homes.

In the rural regions of Africa and Asia, people have devised many uses for sorghum stems. These include:

• Roof thatching;

• Sleeping mats and baskets (made from the peeled stems); and

• Strings in traditional musical instruments (in Nigeria, for example, the peeled bark is used this way¹³).

In China, a particularly strong type has been developed for its pliable, dense stalks. Usually known as galiang sorghum, it is used for constructing fences, walls, and many household items, including grain bins bigger than the beds of pick-up trucks.

Broomcorn belongs to this special galiang group of sorghums. It is a special sorghum that is grown not for food, forage, or fuel but for the bristles that rise from its flower head (inflorescence). These stiff, very strong, strawlike projections can be up to 60 cm long. For several centuries, people have used them to make brooms and brushes.