The number of figures depicted varies greatly, depending on the amount of room available for the design. As a maximum, if the longer ancestry from Luke is used, there are 43 generations between Jesse and Jesus. The identity of the figures also varies, and may not be specified, but Solomon and David are usually included, and often all shown wear crowns. Most Jesse Trees include Mary immediately beneath the figure of Jesus (or, in the Gothic period, show a Virgin and Child), emphasising that she was the means by which the shoot of Jesse was born. See for example, Sermon 24 of St Leo the Great: "In which rod, no doubt the blessed Virgin Mary is predicted, who sprung from the stock of Jesse and David and fecundated by the Holy Ghost, brought forth a new flower of human flesh, becoming a virgin-mother". Saint Joseph is rarely shown, although unlike Mary he is a link in the Gospel genealogies. It was believed in the Middle Ages that the House of David could only marry within itself, and that she was independently descended from Jesse. Sometimes Jesus and other figures are shown in the cups of flowers, as the fruit or blossom of the Tree.