Seaweed, the common name for many kinds of marine algae. Although the name is sometimes used for all of the marine algae, most botanists restrict the term to the larger algae that are attached or have been attached to the sea bottom. The brown algae, including the kelps, and the red algae are most commonly called seaweeds. Kelp is used as food and as fertilizer in the Far East. Kelp and red algae are frequently used as animal feed in Europe.
Cucumber, a trailing vine of the gourd family. Its green fruit -- usually long and warty with crisp, white flesh -- is sliced and eaten raw in salads, or pickled with dill or other spices and eaten as a relish.
As the human population soars, our ability to feed all those hungry mouths can't keep pace. How did an English economist by the name of Thomas Malthus wind up thinking about this very issue in the 19th century, and what's his connection to Darwin?