Search results
Results from the WOW.Com Content Network
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.
A pistil typically consists of an expanded basal portion called an ovary, an elongated section called a style and an apical structure called a stigma that receives pollen. The ovary (from Latin ovum , meaning egg) is the enlarged basal portion which contains placentas , ridges of tissue bearing one or more ovules (integumented megasporangia ).
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.
The ovules are attached to parts of the interior ovary walls called the placentae. Placental areas occur in various positions, corresponding to various parts of the carpels that make up the ovary. See Ovule#Location within the plant. An obturator is present in the ovary of some plants, near the micropyle of each ovule.
A floral diagram is a graphic representation of the structure of a flower. It shows the number of floral organs, their arrangement and fusion. Different parts of the flower are represented by their respective symbols. Floral diagrams are useful for flower identification or can help in understanding angiosperm evolution.
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. Among all living organisms, flowers , which are the reproductive structures of angiosperms , are the most varied physically and show a correspondingly great diversity ...
In seed plants, a structure called the ovule contains the female gametophyte. The gametophyte produces an egg cell. After fertilization, the ovule develops into a seed containing the embryo. [14] In flowering plants, the female gametophyte (sometimes referred to as the embryo sac) has been reduced to just eight cells inside the ovule.
Diagram showing the stigma-style-ovary system of the female reproductive organ of a plant. The stigma is fixed to the apex of the style , a narrow upward extension of the ovary . The stigma ( pl. : stigmas or stigmata ) [ 1 ] is the receptive tip of a carpel , or of several fused carpels, in the gynoecium of a flower .