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A fruit is the mature, ripened ovary of a flower following double fertilization in an angiosperm.Because gymnosperms do not have an ovary but reproduce through fertilization of unprotected ovules, they produce naked seeds that do not have a surrounding fruit, this meaning that juniper and yew "berries" are not fruits, but modified cones.
Diagram of an ovule in gymnosperms and angiosperms Photomicrograph of an ovule of a monocotyledon. In angiosperms the gynoecium, also called pistil, consists of one or more carpels or carpel leaves that form a cavity, the ovary, inside which the ovules or seminal primordia are protected from both desiccation and attack by phytophagous insects.
They can be generalized to show the typical floral structure of a taxon. [1]: 37 It is also possible to represent (partial) inflorescences by diagrams. A substantial amount of information may be included in a good diagram. It can be useful for flower identification or comparison between angiosperm taxa.
Location of ovules inside a Helleborus foetidus flower. In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the integument, forming its outer layer, the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center.
The term angiosperm fundamentally changed in meaning in 1827 with Robert Brown, when angiosperm came to mean a seed plant with enclosed ovules. [35] [36] In 1851, with Wilhelm Hofmeister's work on embryo-sacs, Angiosperm came to have its modern meaning of all the flowering plants including Dicotyledons and Monocotyledons.
In ferns, gymnosperms, and flowering plants (angiosperms), the gametophytes are relatively small and the sporophyte is much larger. In gymnosperms and flowering plants the megagametophyte is contained within the ovule (that may develop into a seed) and the microgametophyte is contained within a pollen grain.
A carpel has a similar function to a megasporophyll, but typically includes a stigma, and is fused, with ovules enclosed in the enlarged lower portion, the ovary. [22] In some basal angiosperm lineages, Degeneriaceae and Winteraceae, a carpel begins as a shallow cup where the ovules develop with laminar placentation, on the upper surface of the ...
In angiosperms, the sporangia are located in the stamen anthers (microsporangia) and ovules (megasporangia). The specialised sporangia bearing stem is the flower . In angiosperms, if the female sporangium is fertilised , it becomes the fruit , a mechanism for dispersing the seeds produced from the embryo.