Types of Inflorescence in Plants: Complete Botany Guide

Botany Sir Himansu

Inflorescence — Text Transcription

1. Inflorescence

Anthotaxis — flower arrangement

Arrangement of flowers on floral axis is called inflorescence.

Note

If a single flower is present in the axil of leaf or at the apex of branch, then it is called solitary inflorescence.

Solitary:

  • Terminal
  • Axillary

Stalk of inflorescence: Peduncle

Types of inflorescence:

  1. Racemose
  2. Cymose
  3. Special

Special types

  1. Cyathium
  2. Hypanthodium
  3. Verticillaster

2. Racemose and Cymose

Racemose

  1. Growth of floral axis is continued — continued floral axis.
  2. Arrangement of flowers is acropetal succession.
    • Old flower at base
    • Young flower at apex
  3. Opening of flowers is centripetal.

Cymose

  1. Growth of floral axis is terminal, due to formation of flower at apex.
  2. Arrangement of flowers is basipetal succession.
    • Old flower at apex
    • Young flower at base
  3. Opening of flowers is centrifugal.

Types of Racemose Inflorescence

Floral axis elongated:

  1. Raceme
  2. Spike
  3. Spikelet
  4. Catkin
  5. Spadix

Floral axis shortened:

  1. Corymb
  2. Umbel

Floral axis flattened:

  1. Capitulum

Raceme

All flowers pedicillate.

Family:

  • Brassicaceae — Radish
  • Fabaceae — Bean

Raceme — Floral axis elongated and all flowers are pedicillate.

3. Spike

All flowers sessile (without pedicel).

Example:

  • Achyranthus
  • Amaranthus

If raceme is branched, it is called compound raceme / panicle.

Example:

  • Gold mohar

Spikelet

Short form of spike.

Three types of bracts are present:

  • Glume
  • Lemma
  • Palea

Family: Poaceae

Examples:

  • Wheat
  • Rice
  • Maize
  • Sugarcane

Wheat

Inflorescence of wheat is called spike or spike of spikelets.

Each spikelet consists of several flowers.

Maize

Tassel — male inflorescence.

Cob — female inflorescence.

4. Catkin

Catkin — pendulous spike with unisexual flowers.

Examples:

  • Mulberry — Morus alba
  • Acalypha

5. Spadix

Spike with a thick floral axis.

Spathe — type of bract present.

Example:

  • Coconut
  • Palm

Compound Spadix

Examples:

  • Coconut
  • Palm

6. Corymb

Compound raceme.

All flowers are pedicillate.

Flowers originate from different points of the flower axis.

Length of pedicel gradually decreases, hence all flowers are at the same level.

Example:

  • Candytuft — Brassicaceae
  • Iberis amara

Mustard inflorescence is called corymbose raceme.

7. Umbel

Simple Umbel

Example: Hydrocotyle

Compound Umbel

Example:

  • Umbelliferous plants
  • Coriander
  • Carrot
  • Fennel

Scapigerous Umbel

Example: Onion

8. Capitulum

Examples:

  • Zinnia
  • Chrysanthemum
  • Cosmos
  • Marigold

Family: Asteraceae

Example:

  • Parthenium — Congress grass

Floral axis is flattened, called receptacle, bearing ray florets and disc florets.

Two types of flowers

  1. Ray floret
  2. Disc floret

9. Cymose Inflorescence

Types of Cymose Inflorescence

  1. Uniparous
    • Scorpiod
    • Helicoid
  2. Biparous
    • Dichasial
    • Brachylytum
  3. Multiparous
    • Polychasial

Uniparous Cymose

Scorpioid — example: Solanum

Helicoid — example: Heliotropium

Special Inflorescence

  1. Cyathium — Euphorbia
  2. Hypanthodium — Ficus
  3. Verticillaster — Ocimum, Salvia

Family of Salvia: Labiatae

Cyathium

  • Poinsettia — Euphorbia
  • Cup-like involucre
  • Male flower
  • Female flower
  • Receptacle

Hypanthodium

  • Example: Ficus
  • Special inflorescence
  • Receptacle
  • Male flowers
  • Female flowers

Verticillaster

Examples:

  • Ocimum
  • Salvia