Hermaphroditism occurs in the great majority of flowering
plants: Monoclinous plants have hermaphrodite, or perfect,
flowers, each of which has both male and female elements
(stamens and carpels); monoecious plants have flowers containing
only male elements and others containing only female elements,
both occurring on the same plant. Only a few flowering plants
are dioecious, that is, carrying male and female organs on
different plants. Most hermaphroditic plants produce male and
female elements at different times to ensure cross-pollination;
a few, such as the violet and the evening primrose, are
habitually self-pollinated. Hermaphroditism habitually occurs in
many invertebrate animals, in the hagfish and tunicate, and in
the sea bass of the genus Serranus. It occurs occasionally in
other fishes, in frogs, toads, and certain newts among the
amphibians. Hermaphrodite animals are rarely self-fertilizing;
in most cases the spermatozoa and ova mature at different times
(successive hermaphroditism), or the male a