Lily or billy- y the difference?

Most flowering plant species are either hermaphroditic, with flowers that produce both male and female gametes, or monoecious, bearing unisexual flowers of both sexes (see Table 1 for some examples). The meeting highlighted recent research on the variety of plant sex-determination and sex chromosomes. Some dioecious plants (species with separate unisexual plants) have no cytologically recognizable sex chromosomes but, like many animals, many have X/Y systems with a single male-determining Y chromosomes (see Table 1). Variants such as X/Y1/Y2, Z/W, and X-autosome balance systems also occur (John Parker, Cambridge Univ. Botanic Garden).