2.2 Anatomy of Flowering Plants

Plant Tissues

  • Meristematic Tissues: Actively dividing cells for growth.
    • Apical: Tips of roots and shoots (length).
    • Intercalary: Between mature tissues (regeneration).
    • Lateral: Sides of roots and shoots (girth).
  • Permanent Tissues: Differentiated cells with specific functions.
    • Simple: Parenchyma, Collenchyma, Sclerenchyma.
    • Complex: Xylem, Phloem.

Simple & Complex Tissues

  • Simple Tissues:
    • Parenchyma: Storage, photosynthesis.
    • Collenchyma: Flexible support.
    • Sclerenchyma: Rigid support (fibres, sclereids).
  • Complex Tissues:
    • Xylem: Water transport (tracheids, vessels).
    • Phloem: Food transport (sieve tubes, companion cells).

Tissue Systems

  • Epidermal Tissue System: Outer protective layer (epidermis, stomata, trichomes).
  • Ground Tissue System: Bulk of the plant body (parenchyma, collenchyma, sclerenchyma).
  • Vascular Tissue System: Transport (xylem and phloem in vascular bundles).

Dicot vs. Monocot Root

Feature Dicot Root Monocot Root
Vascular Bundles Diarch to hexarch Polyarch (more than 6)
Pith Small or absent Large and well-developed
Secondary Growth Present Absent

Dicot vs. Monocot Stem

Feature Dicot Stem Monocot Stem
Vascular Bundles Arranged in a ring, open Scattered, closed
Ground Tissue Differentiated into cortex and pith Not differentiated
Secondary Growth Present Absent

Dicot vs. Monocot Leaf

Feature Dicot Leaf (Dorsiventral) Monocot Leaf (Isobilateral)
Stomata More on lower epidermis On both surfaces
Mesophyll Differentiated into palisade and spongy parenchyma Not differentiated
Bulliform Cells Absent Present in some grasses