University of Santo Tomas
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
Exercise 6: Plant Tissues • First derivative of promeristem
• Retains meristematic properties of continuous division
Vascular plant tissue: derived from the product of fertilized egg
• Situated at the tips of the root, stem, and appendages
(zygote) that has undergone repeated cell division
• Cells divide repeatedly, develop and mature to form
primary permanent tissues that make the primary
Tissues
structure/plant body
•
Meristematic Permanent
tissues tissues E.g. apical meristem at the root and shoot apex
Origin &
Location Simple Complex
development
Primary
Secondary meristem
Promeristem Apical Intercalary Parenchyma Collenchyma Xylem Phloem
• Gives rise to secondary tissue for plants exhibiting
meristem
Secondary
meristem
Lateral Sclerenchyma
secondary growth
Function • E.g. lateral and intercalary meristems, vascular and
Protoderm Procambium
cork cambium
Ground
meristem
Classification based on position (location)
TISSUES Apical meristem
• Group of cells performing a specific function • Cells can differentiate into various cell types
• Gives rise to primary tissues to form primary plant body
Classification based on stage of development • Growth region in root tips, tips of new shoots and leaves
Embryonic/meristematic Intercalary meristem
• Undifferentiated cells • Associated with growth, length, and elongation
• Meristematic: actively dividing cells; in mitotic state • Situated in the stem, base of nodes, and leaf plates
• Capable of rapid growth and regrowth
Permanent • E.g. intercalary tissue at base of blade of grass allows it
• Mature, differentiated cells to regrow after being cut
Classification based on composition Lateral meristem
• To grow in diameter
Simple
• To increase girth or thickness as part of secondary
• One type of cells
growth
• E.g. vascular cambium, cork cambium
Complex
• Different types of cells
Classification based on initiating cells (origin)
Promeristem (primordial meristem)
• Group of young cells of a growing organ
• Occupies a small area at the tip of the stem and root
• Further divides to form primary meristem
Primary meristem
Classification based on function
1|P a g e
LIANRPh
, University of Santo Tomas
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
Protoderm meristem (dermatogen) • E.g. cotton trichomes can be made into threads to
• Develops to form dermal tissue system (epidermis) weave cloth
Procambium (plerome) Glandular/secretory trichomes
• Gives rise to vascular tissue system (xylem, phloem)
Fundamental/ground (periblem)
• Gives rise to ground tissue system that forms
hypodermis, cortex, and pith
DERMAL TISSUE (EPIDERMIS)
• Outermost surface of herbaceous stem, leaf, and root
Non-glandular trichomes
• For protection
• Regulates the exchange of materials
Stinging
• Irregular, isodiametric, distinctly elongated
• Encrusted with cutin
o Cuticle layer of plants prevents water loss and plant
dehydration
o Cutin inhibits CO2 entry for photosynthesis
o Guard cell pairs with stomatal pore between cutin to
permit CO2 entry
o Stomatal pores are open during daytime for
photosynthesis Bristle
Accessory cells
• Reservoir of water and ions
Bulliform cells (motor cells)
• Longitudinal rows of vacuolated cells
• Large, bubble-shaped, may be white or colorless
• Found on top surface of leaves (midvein) in groups of
Scale
multiple monocots
• Prevents water loss via transpiration
Epidermal hairs/trichomes
• Elongation of epidermal cells outwards
• Increases surface area of roots for higher water
absorption
• Aids in nutrient uptake
• For protection against insects and excessive sunlight Stellate
o Thorn-like structures can be defensive structures
• Secretory gland for salt, antiherbivore compounds
• Spread of seeds
2|P a g e
LIANRPh
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
Exercise 6: Plant Tissues • First derivative of promeristem
• Retains meristematic properties of continuous division
Vascular plant tissue: derived from the product of fertilized egg
• Situated at the tips of the root, stem, and appendages
(zygote) that has undergone repeated cell division
• Cells divide repeatedly, develop and mature to form
primary permanent tissues that make the primary
Tissues
structure/plant body
•
Meristematic Permanent
tissues tissues E.g. apical meristem at the root and shoot apex
Origin &
Location Simple Complex
development
Primary
Secondary meristem
Promeristem Apical Intercalary Parenchyma Collenchyma Xylem Phloem
• Gives rise to secondary tissue for plants exhibiting
meristem
Secondary
meristem
Lateral Sclerenchyma
secondary growth
Function • E.g. lateral and intercalary meristems, vascular and
Protoderm Procambium
cork cambium
Ground
meristem
Classification based on position (location)
TISSUES Apical meristem
• Group of cells performing a specific function • Cells can differentiate into various cell types
• Gives rise to primary tissues to form primary plant body
Classification based on stage of development • Growth region in root tips, tips of new shoots and leaves
Embryonic/meristematic Intercalary meristem
• Undifferentiated cells • Associated with growth, length, and elongation
• Meristematic: actively dividing cells; in mitotic state • Situated in the stem, base of nodes, and leaf plates
• Capable of rapid growth and regrowth
Permanent • E.g. intercalary tissue at base of blade of grass allows it
• Mature, differentiated cells to regrow after being cut
Classification based on composition Lateral meristem
• To grow in diameter
Simple
• To increase girth or thickness as part of secondary
• One type of cells
growth
• E.g. vascular cambium, cork cambium
Complex
• Different types of cells
Classification based on initiating cells (origin)
Promeristem (primordial meristem)
• Group of young cells of a growing organ
• Occupies a small area at the tip of the stem and root
• Further divides to form primary meristem
Primary meristem
Classification based on function
1|P a g e
LIANRPh
, University of Santo Tomas
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
Protoderm meristem (dermatogen) • E.g. cotton trichomes can be made into threads to
• Develops to form dermal tissue system (epidermis) weave cloth
Procambium (plerome) Glandular/secretory trichomes
• Gives rise to vascular tissue system (xylem, phloem)
Fundamental/ground (periblem)
• Gives rise to ground tissue system that forms
hypodermis, cortex, and pith
DERMAL TISSUE (EPIDERMIS)
• Outermost surface of herbaceous stem, leaf, and root
Non-glandular trichomes
• For protection
• Regulates the exchange of materials
Stinging
• Irregular, isodiametric, distinctly elongated
• Encrusted with cutin
o Cuticle layer of plants prevents water loss and plant
dehydration
o Cutin inhibits CO2 entry for photosynthesis
o Guard cell pairs with stomatal pore between cutin to
permit CO2 entry
o Stomatal pores are open during daytime for
photosynthesis Bristle
Accessory cells
• Reservoir of water and ions
Bulliform cells (motor cells)
• Longitudinal rows of vacuolated cells
• Large, bubble-shaped, may be white or colorless
• Found on top surface of leaves (midvein) in groups of
Scale
multiple monocots
• Prevents water loss via transpiration
Epidermal hairs/trichomes
• Elongation of epidermal cells outwards
• Increases surface area of roots for higher water
absorption
• Aids in nutrient uptake
• For protection against insects and excessive sunlight Stellate
o Thorn-like structures can be defensive structures
• Secretory gland for salt, antiherbivore compounds
• Spread of seeds
2|P a g e
LIANRPh
