Health effects of chocolate no medical or regulatory authority has approved any health claim. "Theobroma cacao", the cacao tree, produces seeds containing flavanols. The seeds have been used to make beverages for some 2000 years in Aztec, Olmec, and Maya civilizations in central and south America. The drinks were ascribed a wide variety of curative and stimulant properties, unsupported by experimental evidence. In the 19th century, chocolate as a solid was invented, and milk and sugar were added to create milk chocolate, high in fat and sugar. Doubtful research, sometimes funded by the chocolate industry, has at times made suggestions of possible health benefits
Tree and frost, and the seed germinates in the spring. Pine cones may similarly be hoarded by red squirrels, and grizzly bears may help to disperse the seed by raiding squirrel caches. The single extant species of Ginkgophyta ("Ginkgo biloba") has fleshy seeds produced at the ends of short branches on female trees, and "Gnetum", a tropical and subtropical group of gymnosperms produce seeds at the tip of a shoot axis. The earliest trees were tree ferns, horsetails and lycophytes, which grew in forests in the Carboniferous period. The first tree may have been "Wattieza", fossils of which have been found