Linnaeus in his _Species Plantarum_ of 1753, gives seven species as belonging to this genus, three of which are credited to America. One, however, _Vitis arborea_, is not classed among the grapes by present-day botanists. Marshall,[114] the first American botanist we have to consider, for neither Tournefort nor Linnaeus had ever been on this continent, in his _Arbustrum Americanum_, 1785, describes the genus Vitis in terms so nearly identical with those of Linnaeus as to lead one to suspect that it is merely a translation from the _Genera Plantarum_. Marshall gives five species. One of these is certainly not a grape and one other is indeterminate. Thomas Walter,[115] in his _Flora Caroliniana_, 1788, gives a brief description of the genus very similar to the foregoing but he also speaks of the masculine and feminine forms of the flowers, a point that does not seem to have been noticed by any botanist of an earlier date. He speaks of the corolla adhering at the top and coming off as a cap, one of the distinguishing characters of Vitis. This latter point had, however, been noted by Tournefort, and his figures show that this is what he means when he speaks of the flower as folding upward. Tournefort, however, seems to have been under the mistaken impression that Ampelopsis (_Ampelopsis quinquifolia_ Michx. is our common American form) opens its flowers in the same way, as he includes this under Vitis. Walter gives only three species and his descriptions of these are very brief. The first European botanist who made an extensive study of American plants in their habitats was André Michaux, a French botanist who traveled extensively in North America at about the close of the eighteenth century. In his _Flora Boreali-Americana_, which was published in 1803, he gives a brief generic description of Vitis which includes all of the essential characters given by Walter. He also questions the male and female characters mentioned by Walter.[116] Michaux mentions five species of the American grapes. His descriptions are clear and every species described can readily be recognized so that there is no question among botanists as to what species was meant in any instance. An interesting contribution to our knowledge of the grapes of North America is that of William Bartram.[117] Bartram's opportunities for becoming familiar with these plants were probably greater than those of any other person of his day, he being a resident of America, and his father having been a botanist, so that he was trained from childhood to observe plants. The following is an extract from an article of Bartram's in the _Domestic Encyclopedia_, 1804: