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Floral Anatomy and Gynesium Structure

• Position of the Gynesium

  • The gynesium is positioned superior relative to other floral organs.

• Description of Gynesium in Images

  • Appears as a green spike-like structure; identified as the floral receptacle.
  • Contains style and stigma of carpels inserted onto an elongate, narrowly conical floral receptacle.
  • When transitioning from a flower to fruit stage, the structure remains identifiable.

• Carpals

  • Number: Numerous.
  • Fusion: Free carpals, tightly pressed against one another but exhibit no fusion.
  • Their arrangement is helical, similar to pineapple segments, in multiple fruits.

• Types of Fruit

  • Identified as aggregate fruit made of multiple free carpals, meaning each carpel matures into a separate fruitlet known as a follicle.
  • Each caul is indehiscent, leading to the conclusion that the fruit is an aggregate of samaras.

• Examination Questions

  • Review questions may be more complex than exam questions; understanding the gynecium across images provides clarity for assessments.

Floral Structure in Buckwheat Family

• Flower Structure

  • One perianth whorl present.
  • Veracity of the Perianth: Five parts.
  • Total Whorls of Stamens: Two, comprising an outer whorl of five and an inner whorl of three.

• Gynesium Characteristics

  • Total Styles: Three.
  • Total Carpels: Three (one style indicates three distinct carpals).
  • Position of Ovary: Largely superior, although partially sunk into the floral receptacle.
  • Presence of Nectaries: Structures recognized as nectariferous tissues.

Typical Lily Flower Structure

• Symmetry

  • The symmetry is radial; divisible like a pie.

• Perianth Structure

  • Consists of tepals; all parts appear uniform in appearance.
  • Number of Whorls: Two whorls each containing three tepals.

• Andresium Structure

  • Configuration mirrors that of perianth, evidencing the standard monocot organization of flowers.

• Carpals Overview

  • Structure called gynecium encompasses all carpals.
  • Position of Ovary: Determined to be superior based on attachment point of floral organs.
  • Term for this flower relative to ovary position: Hypogenous.

Trillium Structure

• Symmetry

  • Exhibits radial symmetry.

• Perianth Differentiation

  • Calyx: Green sepals.
  • Corollas: Petalloid petals.

• Stamen and Carpal Composition

  • Total Stamen: Six.
  • Classification of Gynesium: Syncarpus, as some styles are free and the ovary is fused.
  • Flowers are confirmed to be hypogenous due to the ovary's superior position in relation to the other floral parts.

Cactus Flower Structure

• Position of Ovary

  • Observed placement of ovary denotes it as inferior.

• Placentation Type

  • Identified as parietal placentation, wherein ovules are arranged along the ovary wall without compartmented locules.

Sunflower Inflorescence

• Inflorescence Type

  • Identified as capitulum or head, featuring a foreshortened disc-like axis with numerous flowers.

• Ovary Position

  • Each flower possesses an inferior ovary.

• Characteristic Variations Among Flowers

  • Flowers display differences primarily in size and age.
  • Peripheral flowers exhibit bilateral symmetry, while central ones have radial symmetry.

Midfamily Flower Structure

• Inflorescence Type

  • Indeterminate arrangement seen with older flowers at the base and younger ones at the apex.

• Flower Symmetry

  • Confirmed as bilateral symmetry due to the presence of a single plane of symmetry.

• Perianth Differentiation

  • Green sepals make up calyx, and brightly colored, petalloid petals form the corolla.

• Number of Stamens Present

  • One whorl of four stamens.

• Nectar Structure

  • The yellowish structure at the base is recognized as a nectary.

• Position of Ovary

  • Confirmed superior relative to surrounding floral structures.