Corolla

What is the use of pappus ?

Corolla

Corolla is the most attractive part in majority of the flowers and is usually brightly coloured. Corolla helps to display the flower and attracts the pollinators.

1. Fusion:

a. Apopetalous (polypetalous, choripetalous): Petals are distinct. Example: Hibiscus.

b. Sympetalous (gamopetalous): Petals are fused. Example: Datura.

2. Shapes of corolla

I. Apopetalous Actinomorphic

1. Cruciform: Four petals arranged in the form of a cross. Example: Brassica, mustard, radish, cauliflower.

2. Caryophyllaceous: Five petals with long claws with limb at right angles to the claw. Example: Caryophyllaceae. Dianthus.

3. Rosaceous: Five to many sessile or minutely clawed petals with radiating limbs. Example: Rose, Tea.

II. Apopetalous Zygomorphic

Papilionaceous:

Made up of five distinct petals organized in a butterfly shape. Corolla has three types of petals. One usually large posterior petal called vexillum(standard)two lateral petals-wings (alae) and two anterior sympetalous petals called carina. Example: Clitoria ternatea, Pea, Bean.

III. Sympetalous Actinomorphic

1. Tubular:

Petals united to form a narrow tubular structure with very short limbs. Example: Disc floret of sunflower.

2. Campanulate:

Petals fused to form a bell-shaped corolla. Example: Physalis,Cucurbita maxima, Campanula.

3. Infundibuliform:

Petals fused to form funnel-shaped corolla. Tube gradually widens into limbs. Example: Datura, Ipomoea.

4. Rotate:

Petals fused to form a wheel shaped corolla with very short tube and a spreading circular limb. Example: brinjal, Evolvulus

5. Salver shaped or Hypocrateriform;

Petals fused to form a long narrow tube with spreading limbs. Example: Catharanthus, Ixora, Tabernaemontana

6. Urceolate:

Petals fused to form urn-shaped or pot-shaped corolla.Example: Bryophyllum calycinum, Diospyros.

IV. Sympetalous Zygomorphic

1. Bilabiate:

Corolla with two lips. Example: Ocimum,Leucas,Adhatoda.

Tubular corolla with a single strap-shaped limb. Example: Ray floret of Helianthus

2. Personate:

Corolla made up of two lips with the upper arched and the lower protruding into the corolla throat. Example: Antirrhinum,Linaria.

3. Ligulate:

Tubular corolla with a single strap-shaped limb. Example: Ray floret of Helianthus.