Flowers and inflorescences – What is a flower?

 Generally, it isbisexual, that is, it bears both male and female reproductive organs.

The asda flowers consists of floral pieces inserted on a floral receptacle.

When the asda flowers is complete, it includes four whorls of floral pieces. From the outside to the inside, we meet:

– The chalice, formed by all the sepals,

– The corolla, formed by all the petals.

– The androecia, that is to say all the stamens (male part), which produce the pollen.

– The gynoecium or pistil, formed by all the carpels (female part).

Chalice and corolla form the periapt, a sterile envelope, which plays a protective role for fertile parts and attractive for pollinating animals.

 Types of flowers:

We distinguish different types of flowers according to:

  • • The chalice:
  • It is formed of sepals that can be free or welded together.
  • Free sepals
  • = dial sepal calyx
  • Ex: Common Ebonite
  • Sepals welded
  • = gamosépale chalice
  • Ex: Geranium Robert
  • He corolla:
  • It is formed of petals, which can also be free or welded.
  • Free petals
  • Ex: cinquefoil
  • Welded petals
  • = calyx gam petals
  • Ex: Campanula Rapunzel
  • Petal corolla with a spur
  • Ex: Violets of dogs

 Floral symmetry:

Regular asda flowers (actinomorphs) are symmetrical with respect to a center.

Irregular asda flowers (zygomorphs) have a bilateralsymmetry: they are symmetrical with respect to a plane.

Ex: Sainfoin

 Inflorescences:

They are said to be “indefinite” when the bud that occupies the top of the central axis does not produce a flower (in this case, the growth is theoretically unlimited) and “defined “when the main axis carries a single flower at its end. . .

• Undefined simple inflorescences:

The main axis is in principle prolonged growth and the pedicels flowers are born directly on this axis. Flowering is progressively from the base to the top or from the outside to the inside.

We distinguish mainly:

  • G rape (or raceme)
  • The main axis carries flowers whose pedicels diminish inlength as one approaches the top of the axis.
  • Cluster with sessile flowers (that is to say withoutpedicel).
  • There are particular ears:
  • Spikelet (in the Phocaea)

Inflorescence carrying at base 2 bracts (glumes). Each flower is born in the armpit of 2 bracts. The spikelets are themselves grouped into inflorescences: on the cob if they are sessile, in clusters if they are pedunculated.

Kitten (in the trees)

Epi composed of unisexual flowers (thus we distinguish maleand female ears) fixed on a short, non-woody axis, coming from a bud on theligneous branch.

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