Biology 215

Plants for Pleasure & Profit

Why horticulture?

• Economical

• Value– Enhanced property value– Reduced costs– Can provide a career, living

• Exercise

Why horticulture?

• Emotional value

Why horticulture?

• Provide animal habitat

Horticulture is a business

• Park Seeds

• Jackson & Perkins

• Lancaster Farms

• Encore azaleas

• Witherspoon Roses

• Plant Delights

Horticulture is a science

• NCSU Horticulture– Horticulture information leaflets

• Journals– Journal of the American Society of Horticult

ural Science– Journal of Horticultural Science & Biotechn

ology

Plant Classification

• Botanical

• Horticultural

Scientific & binomial nomenclature

Brassica oleracea cv. Green Comet

Lycopersicon esculentum cv. Better Boy

Hibiscus syriacus ‘Diana’

Phlox

P. paniculata P. subulata

Growth cycles

Growth cycles

• Annuals

Growth cycles

• Biennials

Growth cycles

• Perennials

Growth cycles

• Monocarps

Growth habit classification

procumbent erect

climbing

SpreadingArchingVertical

Ornamental plant classifications

• Herbaceous vs. woody

• Flowering vs. foliage

• Hardiness zones

Herbaceous plants

• Annuals, biennials, perennials

Woody plants

• Vines• Shrubs

• Trees

Shrubs

Trees

Flowering vs. foliage plants

Hardiness classification

Plant anatomy

Dicots Monocots

storage roots

Mycorrhizae

fungal association (mutualistic) with roots

Stems

•Support

•Conduction

•Growth

Stem functions

Leaf Functions?

•Photosynthesis•Conduction•Protection

Leaves

Leaf characteristics

Flowers

Organs for reproduction

Flower anatomy

Perfect vs. imperfect flowers

• Perfect – having both male and female parts

• Imperfect – lacking male or female parts

Imperfect flowers

• Monoecious species– Staminate and pistillate flowers on

the same plant– Oaks, maples, pines, corn, melons,

figs, pecans (dichogamous)

Imperfect flowers

• Dioecious species– Staminate and pistillate

flowers on separate plants– Gingko, kiwi, persimmon,

cannabis

Flower development

• The ABC model of flower development– A,B,C = differententially expressed MADS

box genes (transcription factors)

Flowers may lack specific flower parts due to mutations in A, B, or

C genes

Flowers are contained on an inflorescence

Determinate vs. indeterminate inflorescences

• Determinate – stem growth ends with a flower(s)

• Indeterminate – flowers produces along stem (at nodes), stem tip continues to grow

Timing of flowering

• How does a plant “know” when to flower?

•Light (intensity and/or daylength)•Temperature•Hormones

Flower pollination and fertilization

Self-incompatibility

Fruit anatomy