STEM

plumule

External Morphology of the Stem

DICOT MONOCOT

Shoot Apex Organization

Anatomy: Primary Structures: Monocot

Anatomy: Primary Structures: Dicot

Stem Anatomy, Secondary Structure

Primary Meristems

Primary Tissues Secondary Meristems

Secondary Tissues

Protoderm Epidermis Phellem

Ground meristem

Cortex Cork cambium

(phellogen)

Phelloderm

Procambium Primary Phloem

Fascicular cambium

Interfascicular cambium

Vascular cambium

Secondary Phloem

Primary Xylem Secondary Xylem

Xylem Components

• Vessel elements– Short and wide

– Thick walled cells with large diameter

• Fiber– Long, slender, pointed ends– Smallest diameter, darkly stained cells

Xylem Components

Phloem Components

Metamorphosed Stems