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The anatomy of the tepals and petals is similar to that of the sepals. The epidermal cell walls are often convex or papillose, especially on the adaxial side. In many petals, such as those of Brassica napus, the papillae are conical, with a marked cuticular thickening at the apex, and radial striations toward the base. It has been suggested ...
The calyx (the sepals) and the corolla (the petals) are the outer sterile whorls of the flower, which together form the perianth. [17] In some plants, such as Aristolochia , the calyx is the primary whorl, forming a flower up to 20 inches (51 cm) wide, with one sepal growing to a length of 13 feet (4.0 m) – Aristolochia grandiflora , the ...
Distinct petals and sepals would therefore have arisen by differentiation, probably in response to animal pollination. In typical modern flowers, the outer or enclosing whorl of organs forms sepals, specialised for protection of the flower bud as it develops, while the inner whorl forms petals, which attract pollinators.
Flowers consist of a combination of vegetative organs – sepals that enclose and protect the developing flower. Petals attract pollinators, and reproductive organs that produce gametophytes, which in flowering plants produce gametes. The male gametophytes, which produce sperm, are enclosed within pollen grains produced in the anthers.
Petals are usually surrounded by an outer whorl of modified leaves called sepals, that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth, the non-reproductive portion of a flower. When the petals and sepals of a flower are difficult to distinguish, they are collectively called ...
Floral diagram of Anagallis arvensis. [1]: 307 The dot represents the main axis, green structure below is the subtending bract.Calyx (green arcs) consists of five free sepals; corolla (red arcs) consists of five fused petals.
A mature flower. In this example, the perianth is separated into a calyx (sepals) and corolla (petals) The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepals when called a perigone.
open – petals or sepals do not overlap or even touch each other . reduplicate – folded outwards. valvate – margins of adjacent petals or sepals touch each other without overlapping. vexillary – a special type of aestivation occurring in plants like pea; in this type of aestivation a large petal called standard encloses two smaller petals.