9.3 Study of Some Important Families

Families are groups of plants havingvery distinguished common characters.


1. Fabaceae

Habit

Trees, shrubs, or herbs (Pea plantbelongs here)

Root

  • Shows root nodules
  • Pea

    is an erect climber

Leaf
  • Pinnately compound
  • Alternate phyllotaxy

Inflorescence

  • Racemose type (raceme)

Flower

  • Bisexual and zygomorphic

Calyx

  • Five fused sepals (gamosepalous)
  • Imbricate aestivation

Corolla

  • Five free petals (polypetalous)
  • Vexillary aestivation:
    • Vexillum: Outermost
    • Two wings: Lateral petals
    • Two fused petals: Keel

Androecium

  • Ten stamens
  • Arrangement:

    Diadelphous[(9)+1]

    • 9 stamens united by filaments
    • 1 stamen free

Gynoecium

  • Monocarpellary
  • Unilocular ovary (superior)
  • Marginal placenta
Fruit
  • Legume type

Seed

  • Non-endospermic

Floral Formula

 


2. Solanaceae

Habit

Herbs, shrubs, or small trees (Daturaplant belongs here)

Root

  • Tap root system

Stem

  • Erect, woody, branched
  • Underground tuber in potato

Leaf

  • Simple
  • Alternate phyllotaxy
  • Reticulate venation

Inflorescence

  • Cymose type (solitary)

Flower

  • Solitary, bisexual, and actinomorphic

Calyx

  • Five fused sepals (gamosepalous)
  • Valvate aestivation
  • Persistent

Corolla

  • Five fused petals (gamopetalous)
  • Contorted aestivation

Androecium

  • Five stamens
  • Free but

    epipetalous(adhesion with petals)

Gynoecium

  • Bicarpellary and syncarpous
  • Bilocular ovary (superior)
  • Many ovules in axile placentation
  • Arranged on swollen placenta
Fruit
  • Berry or capsule type

Seed

  • Endospermic

Floral Formula