Flower differentiation is a plant process by which the

shoot apical meristem In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic ce ...

changes its anatomy to generate a

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

in lieu of other structures. Anatomical changes begin at the edge of the

meristem In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic c ...

, generating first the outer

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagram ...

of the

- the calyx and the corolla, and later the inner whorls of the flower, the

androecium The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

and

gynoecium Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

. Flower differentiation can take from only a few days (in

annual plants An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are an ...

) to 4–11 months (in fruit crops). The process is preceded by

flower induction Flower induction is the physiological process in the plant by which the shoot apical meristem becomes competent to develop flowers. Biochemical changes at the apex, particularly those caused by cytokinins, accompany this process. Usually flower i ...

Morphological Characteristics: dit

Flower bud differentiation was seen to have five different stages in the flower ''M.sinostellata''. Undifferentiated stage: The flower bud was seen as yellow-green, had no scale hairs and was smooth outside. Its differentiation primordium cells are small and arranged closely. Early flower bud differentiation stage: The bud's basal region begins to expand and develops yellow-brown hairs on its outer surface. The

bract In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

s inside the growing bud begin to stratify. Cells are still closely arranged and the floral primordium becomes larger.

Petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

primordium differentiation stage: At this stage, the bud becomes more distinct than the leaf primordia by becoming longer and wider. The bud develops a couple of spathe-like bracts with scale hairs. The start of petal primordium differentiation is demonstrated by the wave-like surface of the tip of the developing floral

Stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

primordium differentiation stage: The bud has expanded and the outer hairs mentioned earlier have become denser. The inner buds differentiation region forms a rounded hump shape with a smooth tip. The bud meristem inner cells are separate from each other while the outer cells stay small and compact. Rows of small spots were found on the inside of the petal primordia around the bottom of the meristem.

Pistil Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

primordium differentiation stage: The pistil primordia beginning to differentiate is indicated by the multiple round bulges in the upper region of the meristem. During this stage, the bud continues to increase its volume. While the Bud tip continues elongating, its base becomes thick and its top turns into a conical shape. Morphological characteristics of the five differentiation stages in Magnolia sinostellata. Fully developed flower bud: Completed differentiation with the bulges from the last step retained.

References

Plant physiology {{plant-physiology-stub