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Or, with bisexual and at least one of male and female flowers on the same plant. [2] Protandrous: (of dichogamous plants) having male parts of flowers developed before female parts, e.g. having flowers that function first as male and then change to female or producing pollen before the stigmas of the same plant are receptive. [6]
Female (left) and male (right) Argiope appensa, displaying typical sexual differences in spiders, with dramatically smaller males Hammock Spiders (Pityohyphantes sp.) courting. Female left and male right. Many arachnid groups exhibit sexual dimorphism, [45] but it is most widely studied in the spiders.
In dioicy male and female sex organs are on separate gametophytes. [18] Dioecy: a species has distinct individual organisms that are either male or female, i.e., they produce only male or only female gametes, either directly (in animals) or indirectly (in plants). [19] Gonochorism: individuals are either male or female. [19]
Flowering plant species with separate, imperfect, male and female flowers on the same individual are called monoecious. Monoecy only occurs in about 7% of flowering plant species. [ 33 ] Monoecious plants are often referred to as hermaphroditic because they produce both male and female gametes.
In some species of plants, the flowers are imperfect or unisexual: having only either male (stamen) or female (carpel) parts. If unisexual male and female flowers appear on the same plant, the species is called monoecious. [27] However, if an individual plant is either female or male, the species is called dioecious.
In flowering plants, individual flowers may be hermaphroditic (i.e., with both stamens and ovaries) or dioecious (unisexual), having either no stamens (i.e., no male parts) or no ovaries (i.e., no female parts). Among flowering plants with unisexual flowers, some also produce hermaphrodite flowers, and the three types may occur in different ...
Autoicous – produces male and female sex organs on the same plant but on separate inflorescences. Bract – leaf is present below the flower. Cladautoicous – male and female inflorescences are on separate branches of the same plant. Dioicous – having two forms of gametophyte, one form bearing antheridia and one form bearing archegonia.
Primitive land plants such as liverworts and mosses had motile sperm that swam in a thin film of water or were splashed in water droplets from the male reproduction organs onto the female organs. As taller and more complex plants evolved, modifications in the alternation of generations evolved.