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) Made Men Rich" covering timber, wine, rubber, and tobacco. David E. Allen writing in "Medical History" described it as "a thoughtful, thought-provoking, extremely readable work" It has been recommended reading and studied at universities and has been reviewed by the "Library Journal", "The American Historical Review", and "The Atlantic". 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,