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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.
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.
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.
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.
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.
Close-up of a Schlumbergera flower, showing part of the gynoecium (specifically the stigma and part of the style) and the stamens that surround it. Plant reproductive morphology is the study of the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction.
Anatomy of a flower. A flower's anatomy, as defined by the presence of a series of organs (sepals, petals, stamens and carpels) positioned according to a given pattern, facilitate sexual reproduction in flowering plants. The flower arises from the activity of three classes of genes, which regulate floral development: [8]
Plant ovules: Gymnosperm ovule on left, angiosperm ovule (inside ovary) on right. After fertilization, the ovules develop into the seeds. The ovule consists of a number of components: The funicle (funiculus, funiculi) or seed stalk which attaches the ovule to the placenta and hence ovary or fruit wall, at the pericarp.