Basic Horticultural Botany
What is Horticulture?
• Horticulture is the art and science of growing
vegetable, fruit, medicinal and ornamental
plants
• Agronomy covers the food and fiber and
energy crops that are grown on large acreages
and are usually seed propagated
What are Horticultural Plants?
• Fruit
– Tropical : mango, papaya
– Subtropical: Orange, fig
– Temperate: Apple, Pear
• A fruit is an enlarged
ovary with seeds and
attached parts
What are Horticultural Plants?
• Vegetables
– Cool Season: broccoli
• Cauliflower,
spinach,onion
– Warm season
• New Zealand spinach
– In the grocery store
language: Tomatoes,
peppers and squash
• Vegetables Botanically
are plant parts without
ovary/seeds.
What are Horticultural Plants?
• Drugs
– Plants that have medical
use: Echinacea, willow,
Ginkgo
What are Horticultural Plants?
• Condiments/ spices:
– Plants used to make
flavorings: mustard,
curry
What are Horticultural Plants?
• Beverage Plants
–
–
–
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Coffee, Tea,
Herbal Tisanes
Hops for beer
Agave for Tequila
What are Horticultural Plants?
• Ornamental Plants
– Herbaceous – flowers
and foliage plants
• Annuals
• Perennials
– Woody trees and shrubs
• Ornamentals are
planted for shade,
beauty, Climate control,
windbreaks…
Basic Botany/ plant classification
Scientific names , Common names
Kingdom
Division
Class
Order
Family
Genus ( pl. Genera)
species( sp. or spp.)
Cultivar or variety
Plantae
Tracheophyta
Angiospermae
Rosales
Rosaceae
Malus
domestica
‘Honeycrisp’
More terms used to classify plants
• Annuals- completes the life cycle in one
season
• Biennial – usually takes two years to complete
the life cycle ( carrots, cabbage)
• Perennial- usually lives more than 2 years
– Woody – trees and shrubs
• Deciduous/ evergreen
– Herbaceous
• Tender/hardy
Plant Structures
• Flowering plants are divided into to large
groups: monocots and dicots
• Monocot means there is one seed leaf
(Cotyledon) in the seed. Dicot means two seed
leaves.
Vegetative vs
reproductive
• Annual herbaceous
plant
• Leaves, stems and roots
are vegetative but can
be used in asexual
reproduction
• Flowers, seeds are
sexual reproductive
parts
Inside a herbaceous stem
Inside a woody stem
Cell types
• Parenchyma
• Schlerenchyma
• 3 year old woody twig
Modified stems- often used in
propagation
•
•
•
•
Spur
Sucker
Stolon
crown
•
•
•
•
Rhizome
Tuber
Bulb
Corm
Leaf
a stem appendage with a bud at it’s base
Leaf types
Leaf margins
Leaf shapes
leaf
Buds
• Axillary (the bud in the
axil of a leaf)
• Terminal
• Bud scales ( temperate)
• Chilling requirements
• Leaf/flower/mixed
Roots/ Function
• Absorb water and
nutrients
• Anchor the plant in the
soil
• Support the stem
• Food storage
• propagation
• First to emerge from
the seed
• Positive geotaxis
• No nodes
• No leaves or flowers
• Not green unless
exposed to light
• Must have oxygen to
Function
Root vs Stem
Stem cross section
Root cross section
Roots
• Tap root ( dicot)
• Fibrous roots (
monocot)
• Lateral /secondary
root/branch root
• Generally extend
beyond the top
Flowers
• Sexual reproduction
• Built to attract
pollinators
• People can be
considered pollinators
• Can be perfect
(complete)
• Unisexual
• Plants can be
monoecious ( corn)or
dioecious ( Cycads)
Basic plant life cycle
• Dormancy: seeds or buds
fail to grow when given
good conditions.
• Vegetative: seedling to
Juvenile
• Reproductive: when plant
is large enough to flower
• Senescence: ripening of
seed, and fruit, leaf drop
Dormancy
• Hormonal dormancy
– Timed by hormones
many temperate plants
show this ex. Apple trees
• Environmental dormancy
– Cold or dryness keeps seed
from germinating
• Other types in seed
dormancy
Vegetative growth
Reproductive Growth
• The plant has to reach
its mature stage before
it can start flowering. In
tomatoes this happens
in 30+ days after
transplant to the
garden. In Apple trees it
can be 5-7 years
5 Factors of plant growth
•
•
•
•
•
Light
Temperature
Air
Water
nutrients
• These are things the
plant needs from the
environment
Primary Metabolism
• Photosynthesis
– Sunlight
– Chloroplasts in a live
plant
– Carbon dioxide
– Energy is changed from
light to chemical energy (
sugars)
– Oxygen released
– Water is used and
produced
• Respiration
– Energy is released from
sugars for plant energy
– Oxygen is used
– Water is used and
produced
– CO2 is produced
– Happens in dark and in
light
– Occurs in all living cells (
mitochondria)
Photosynthesis
CO2+ H20 +sunlight +green plant
C6H12O6 + O2+ H2O
Respiration
C6H12O6 + O2+ H2O
CO2+ H20 + 36 ATP
Transpiration
99 % of the water that enters the plant is used in Transpiration, 1% in metabolism
Plant growth Regulators
• Plant hormones or other chemicals that influence
growth of plants.
– Auxins
-Gibberellins
– Cytokinins
-Abscisic Acid
– Ethylene