Flower Shapes and their function

Describing Flower Shapes

• As with leaf shapes and the arrangement of flowers, these descriptions can only give you a general idea of the shapes of flowers.

• Very often, flowers are not quite any of these shapes, but are something in between.

• Many flowers in the Campanula family are described as tubular bells, meaning they are rather longer than a bell shape, but still have flared tips

Flower Shapes

Flower Shapes

• Often a flower will start off with a bowl shape, and will open wider even than a saucer and the tips of the petals will curl outwards and under.

• It is often difficult to tell whether any particular flower is a trumpet or a funnel - how much of a tube does it need to be a trumpet, or where exactly is the dividing line between a trumpet and a salver?

Flower Shapes • (Bell-shaped) A flower with a wide tube

and flared lobes (petal tips), typical of the Bellflower family (Campanulaceae).

• The length of the tube is variable, and the open-ness of the flower, but campanulate is generally shorter and fatter than tubular, and more closed than stellate. The example is Campanula spp.

Funnelform

• (Funnel-shaped) A flower that widens

gradually from the base, ending in an open or flared shape. The example is Valotta lily.

Trumpet-shaped

• A flower that starts as a narrow tube, but widens into a flared mouth, where the petals often turn back. The example is Petunia grandiflora, and Lilium longiflorum

Salverform

• A flower with a long, thin tube, that widens suddenly into a flat-faced flower. The example is

• Plumbago auriculata • or Frangipani sp.

Urceolate

• (Urn-shaped) A flower in which the petals are fused into an almost enclosed globe shape, separating at the mouth into individual flared petals. The example is Erica tetralix.

Bowl-shaped

• A flower with a deep dish shape, roughly hemispherical, with straight sides or with a very slight flare at the tips. Much the same as cup-shaped.

Example Poppies, Tulips

Saucer-shaped

• A flower that is almost flat, with slightly upturned petal tips. The example is Geranium wallichianum.

Stellate

• (Star-shaped) A flower with many

narrow petals arising separately from a central point. The example is Oriental Lily

Cruciform

• (Cross-shaped) A flower with four petals at

right angles to one another. Typical of members of the Cabbage Family (Brassicaceae). The example Stock

Papilionaceous

• (Pea-shaped) The flower shape typical

of members of the Fabaceae subfamily Faboideae having a large upper petal called the standard, two large side petals called wings, and two lower petals, often fused together, called the keel, which encloses the stamens and stigma. The example is sweet pea

Tubular

• A cylindrical tube-like flower that does not have spreading petal tips.

Coroniform

• Daffodil (Narcissus) • Flowers with a corona

(crown). • A corona is a group of

petal-like organs between the petals and stamens

Radiate

• Petals radiate from a central section that contains multiple flowers

• Example Zinnia sp.

Doubles

• Double flowers have additional floral organs compared to the usual sets of four, five or six found in most plants.

• The extra organs are usually petals that have

replaced stamens. • A semi-double flower has additional

petals but stamens still remain. • A fully double flower has lost most or

all stamens to petals

• Flowers are the reproductive part of most plants

• Flowers contain pollen and tiny eggs called ovules

• After pollination of the flower and fertilization of the ovule, the ovule develops into a fruit

Function of Flowers

All flowers have some features in common

• Petals are used to attract insects/pollinators such as bees, butterflies and bats into the flower

• Stigma- Is covered in a sticky substance that the pollen grains will adhere to

• Style - raises the stigma away from the Ovary to decrease the likelihood of pollen contamination. It varies in length

• Ovary -this protects the ovule and once fertilisation has taken place it will become the fruit

• Ovule is like the egg in animals and once fertilisation has taken place will become the seed

• Receptacle- this is the flower's attachment to the stalk • Flower stock - gives support to the flower and elevates

the flower for the insects • Sepals protect the flower whilst the flower is developing

from a bud • Filament - this is the stalk of the Anther • Anther - The anther produces pollen (male reproductive

cells

Flower parts

The stigma, style, ovary, and ovule are often known collectively as the Carpel or Pistil or female parts of the flower The filament and the Anthers are collectively known as the Stamen or the male parts of the plant

Fertilisation The joining of pollen with an ovule to form a seed

• During the process of fertilisation, pollen lands on the stigma, a tube grows down the style and enters the ovary.

• Male reproductive cells travel down the tube and join with the ovule, fertilizing it.

• The fertilized ovule becomes the seed, and the ovary becomes the fruit.

• End