Structure and Function of Flowering Plants Flashcards

Vocabulary flashcards covering floral structures, sexuality in flowers, floral whorls, cohesion of stamens, inflorescence, and placentation based on Concise Biology notes.

Flower

A specialized shoot in which the leaves are modified into floral structures.

Pedicel

The stalk that supports the flower.

Sessile

Describes a flower that is attached directly to the stem without a supporting stalk or pedicel.

Thalamus (Receptacle)

The enlarged, cup-shaped tip of the stalk (pedicel) on which the four floral whorls are borne.

Calyx

The first outer floral whorl, composed collectively of green sepals.

Corolla

The second floral whorl, composed collectively of large, brightly-coloured petals.

Androecium

The third floral whorl representing the male reproductive parts of a flower, consisting of stamens.

Gynoecium (Pistil)

The centrally located fourth floral whorl representing the female reproductive parts, formed of one or more carpels.

Complete Flower

A flower that contains all four floral whorls (calyx, corolla, androecium, and gynoecium).

Incomplete Flower

A flower in which one or more sets of floral whorls are missing.

Essential Parts of a Flower

The reproductive whorls directly concerned with reproduction, consisting of stamens (male) and carpels (female).

Non-essential Parts of a Flower

The accessory whorls (sepals and petals) that protect reproductive parts or attract insects for pollination.

Perianth (Tepals)

The collective floral envelope when sepals and petals look very similar and cannot be differentiated from one another.

Sepaloid Perianth

A perianth that is green in appearance, resembling sepals.

Petaloid Perianth

A perianth that is non-green and brightly coloured, resembling petals.

Bract

A leaf-like structure (green or brightly coloured) in whose axil a flower arises, such as the large coloured bracts of Bougainvillea.

Bisexual (Hermaphrodite) Flower

A flower that contains both stamens and carpels, such as hibiscus, rose, lily, and tomato.

Unisexual Flower

An incomplete flower that possesses only male reproductive organs (stamens) or only female reproductive organs (carpels).

Staminate Flower

A unisexual male flower containing only stamens.

Pistillate Flower

A unisexual female flower containing only carpels.

Neuter Flower

A flower in which both male and female reproductive organs are lacking, such as the ray florets of a sunflower.

Polysepalous

A condition of the calyx in which the sepals are completely free from one another.

Gamosepalous

A condition of the calyx in which the sepals are fused or united together.

Epicalyx

An extra whorl of sepal-like structures (episepals) found outside the true calyx, as seen in Hibiscus.

Petaloid Sepals

Sepals that are brightly coloured rather than green, such as the red sepals of Gul Mohur.

Nectaries

Groups of nectar-secreting cells situated usually at the base of the pistil or petals that secrete sweet nectar to attract insects.

Polypetalous

A condition of the corolla in which the petals are free from one another.

Gamopetalous

A condition of the corolla in which the petals are united or fused together to form a tube.

Polyandrous

An androecium condition where the stamens are completely free from one another, as in Petunia.

Monadelphous

A cohesion arrangement where stamens are united in a single bundle by their filaments while their anthers remain free, as in china rose and cotton.

Diadelphous

A cohesion arrangement where stamens are united by their filaments into two separate bundles, as in pea plants.

Polyadelphous

A cohesion arrangement where stamens are united by their filaments into several distinct groups or bundles, as in Bombax.

Stigma

The terminal knob-like part of a carpel, covered with hair or glandular papillae, which serves as the landing place for pollen during pollination.

Style

The tubular slender stalk of a carpel that connects the stigma to the ovary.

Ovary

The swollen basal portion of a carpel containing locules and ovules, which matures into the fruit.

Locules

The inner chambers or compartments within the cavity of an ovary.

Placenta

The vascular tissue inside the ovary that attaches the ovules to the ovary wall.

Placentation

The specific manner in which ovules are arranged or attached to the wall of the ovary.

Monoecious Plants

Plants that bear separate male and female unisexual flowers on the same individual plant, such as maize, cucumber, and pumpkin.

Dioecious Plants

Plants in which male (staminate) and female (pistillate) flowers grow on completely separate individual plants, such as palm and papaya.

Inflorescence

The manner of arrangement of flowers on the axis of a plant.