Common term in biology (intersexuality, zwittrigkeit) for the occurrence of double-sex individuals with male and female sex characteristics. Seed plants are distinguished by two types of zwittrigkeit: so-called monoecious plants have both male and female blossoms but they are separated; for example, on one branch a female organ, on another branch a male organ. In true hermaphroditic plants, both male and female genitalia are united in the flowers. These are called hermaphrodites or hybrids, the flowers as hermaphrodite flower designated. This phenomenon is common in many plants and is cultivated Rebstock the rule. But there are also pure female grape varieties that on pollination are reliant.