Rosaceae

Plant family containing over 3,000 species in about 100 genera, including herbs, shrubs, and trees. Rosaceae species cultivated for their flowers include roses, also species of Spiraea, Geum, and Potentilla, as well as Crataegus (hawthorn) and the various fruit tree genera. The family is also of great economic value for fruit, including Fragaria (strawberry); Rubus (blackberry, loganberry, and raspberry); Prunus (apricot, cherry, peach, and plum); Malus (apple), and Pyrus (pear).

There is a wide range of structure in the family, and few generalisations can be made. However, the genera show clear similarities to one another. Most species have flowers with five sepals, five petals (not joined to each other), numerous stamens, and numerous separate carpels (sections of the ovary). There is usually a more-or-less channelled zone between the stamens and carpels, so that they arise at about the same level in the flower, even though the carpels are often borne on the projecting central part of the flower. Exceptions to this pattern include Alchemilla, with four sepals, no petals, four stamens, and a single carpel; Prunus, with a single carpel; Rosa (rose), Malus (apple), and related genera have carpels attached below the other floral parts and often few in number.