ABSTRACT
The majority of owering plants produce owers that are “perfect.” These owers are both staminate (with stamens) and pistillate (with one or more carpels). In a small number of species, there is spatial separation of the sexual organs either as monoecy, where the male and female organs are found on separate owers on the same plant, or dioecy, where male and female owers are found on separate male (staminate) or female (pistillate) individuals. Sex determination systems in plants, leading to unisexuality as monoecy or dioecy, have undergone independent evolutions. In dioecious plant species, the point of divergence from the hermaphrodite pattern shows wide variations between species, implying that the genetic bases are very different. The Cucurbitaceae family is characterized by the presence of unisexual owers. The sex expression in this family is highly variable, and a single genus can contain both monoecious and dioecious species. This family includes many important vegetables collectively referred to as cucurbits. The Cucurbitaceae is a distinct family without any close relatives. All the cultivated species are found in the subfamily Cucurbitoideae. The plants discussed in this chapter are dispersed among different tribes: Melothrieae (bur gherkins, melon, cucumber), Jalifeae (bitter melon), Benincaseae (wax gourd, watermelon, angled luffa, smooth luffa), Cucurbitaceae (pumpkin, squash), and Sicyeae (chayote). Cucurbit plants have tailing or vining growth habit; they bear tendrils and are frost sensitive and appear annually.
