Search results
Results from the WOW.Com Content Network
Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirally arranged.
An object is said to have symmetry when at least one plane can divide it into two parts, so that each part is the mirror image of the other. Spiral flowers have no plane of symmetry and are said to be asymmetrical or irregular, as in the case of Liriodendron tulipifera (magnoliaceae). However, in the whorled flowers, because there are ...
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, the face of a human being has a plane of symmetry down its centre, or a pine cone displays a clear symmetrical spiral pattern.
Animals mainly have bilateral or mirror symmetry, as do the leaves of plants and some flowers such as orchids. [30] Plants often have radial or rotational symmetry, as do many flowers and some groups of animals such as sea anemones. Fivefold symmetry is found in the echinoderms, the group that includes starfish, sea urchins, and sea lilies. [31]
Parts of plant stem Euonymus alata, an example of alate stems Saraca cauliflora, an example of cauliflora Sciadopitys verticillata, an example of a verticillate plant. Accessory buds – an embryonic shoot occurring above or to the side of an axillary bud; also known as supernumerary bud. Acrocarpous – produced at the end of a branch.
Although plants produce numerous copies of the same organ during their lives, not all copies of a particular organ will be identical. There is variation among the parts of a mature plant resulting from the relative position where the organ is produced. For example, along a new branch the leaves may vary in a consistent pattern along the branch.
To the contrary, plants in the Mimosoideae subfamily of legumes have the petals reduced, and have numerous stamens arranged in showy spikes. In the Caesalpinioideae subfamily of legumes the upper petal is initially enveloped by the lateral petals, before the petals unfold to assume a radial five-fold symmetry. [ 9 ]
Symmetry or arrangement may be described for the whole flower; in such case the corresponding symbol is usually placed at the beginning of the formula. It may be also outlined separately for different organs, placing it after their labels or numbers, or it may not be included in the formula at all.