Seed are sometimes sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed. Different groups of plants have other modifications, the so-called stone fruits (such as the peach) have a hardened fruit layer (the endocarp) fused to and surrounding the actual seed. Nuts are the one-seeded, hard-shelled fruit of some plants with an indehiscent seed, such as an acorn or hazelnut. Seeds are produced in several related groups of plants, and their manner of production distinguishes the angiosperms ("enclosed seeds") from the gymnosperms ("naked seeds"). Angiosperm seeds are produced in
Seeds of Change (book) Seeds of Change (book) Seeds of Change: Five Plants That Transformed Mankind is a 1985 book by Henry Hobhouse which explains how the history of the world since Columbus linked America to Europe and has been changed by five plants. It describes how mankind's discovery, usage and trade of sugar, tea, cotton, the potato, and quinine have influenced history to make the modern world. In the second edition of the book, Seeds of Change: Six Plants that Transformed Mankind, he adds the coca plant to the list. In 2004, he published a follow-up book "Seeds of Wealth: Four Plants That