Tuesday Lecture – Ornamental Plants

Reading: Textbook, Chapter 17

Quiz

Quiz

1.Describe a factor that could result in a plant having a leaf that has a coloration other than solid green.

2.Describe a feature of the UTIA Gardens that you particularly liked.

Naming OrnamentalsDifficulties introduced by the nature of ornamentals:

often hybrids

- many are sterile, propagated vegetatively

- mutants with striking features – propagated vegetatively to retain features

- marketing

International Code of Horticultural Nomenclature – sets of rules governing assignment of cultivar names

Some widely grown plants may have a registry of cultivar names

Naming OrnamentalsDifficulties introduced by the nature of ornamentals:

- often hybrids

- many are sterile, propagated vegetatively

- mutants with striking features – propagated vegetatively to retain features

- marketing

International Code of Horticultural Nomenclature – sets of rules governing assignment of cultivar names

Some widely grown plants may have a registry of cultivar names

Naming OrnamentalsDifficulties introduced by the nature of ornamentals:

- often hybrids

- many are sterile, propagated vegetatively

- mutants with striking features – propagated vegetatively to retain features

- marketing

International Code of Horticultural Nomenclature – sets of rules governing assignment of cultivar names

Some widely grown plants may have a registry of cultivar names

Naming OrnamentalsDifficulties introduced by the nature of ornamentals:

- often hybrids

- many are sterile, propagated vegetatively

- mutants with striking features – propagated vegetatively to retain features

-marketing

International Code of Horticultural Nomenclature – sets of rules governing assignment of cultivar names

Some widely grown plants may have a registry of cultivar names

Naming OrnamentalsDifficulties introduced by the nature of ornamentals:

- often hybrids

- many are sterile, propagated vegetatively

- mutants with striking features – propagated vegetatively to retain features

- marketing

International Code of Horticultural Nomenclature – sets of rules governing assignment of cultivar names

Some widely grown plants may have a registry of cultivar names

Naming OrnamentalsDifficulties introduced by the nature of ornamentals:

- often hybrids

- many are sterile, propagated vegetatively

- mutants with striking features – propagated vegetatively to retain features

- marketing

International Code of Horticultural Nomenclature – sets of rules governing assignment of cultivar names

Some widely grown plants may have a registry of cultivar names

Cultivar Names2. Variation within cultivated plants

- “variety” – widely (and still) used

- cultivar (cultivated variety)

Used to denote an assemblage of cultivated plants that is clearly distinguished by some character(s) and that following reproduction retains its distinguishing character(s)

Cultivar name is written in any language except for Latin

Cultivar name can be combined with a generic, specific, or common name:

Citrullus cv. Crimson Sweet;

watermelon cv. Crimson Sweet;

Citrullus lanatus cv. Crimson Sweet

Types of Ornamentals

1. Nursery Crops – planted outside

- trees/shrubs; turf; ground covers; bedding plants

Types of Ornamentals

1. Nursery Crops – planted outside

- trees/shrubs; turf; ground covers; bedding plants

2. Florist Crops – grown for cut flowers or foliage

- increased worldwide: $12.5 billion (1985) $25 billion (2009)

Types of Ornamentals

1. Nursery Crops – planted outside

- trees/shrubs; turf; ground covers; bedding plants

2. Florist Crops – grown for cut flowers or foliage

- increased worldwide: $12.5 billion (1985) $25 billion (2009)

US – dipped from 4.2 billion (2007) to 3.8 billion (2009)

Types of Ornamentals

1. Nursery Crops – planted outside

- trees/shrubs; turf; ground covers; bedding plants

2. Florist Crops – grown for cut flowers or foliage

- increased worldwide: $12.5 billion (1985) $25 billion (2009)

3. Houseplants – sold for growing indoors

- plants must survive in harsh environment

Asteraceae – The Ornamental Family

- Ageratum

- Aster

- Black-eyed Susan

- Cornflower

- Dahlia

- Daisy

- Marigold

- Chrysanthemum (Dendranthemum)

- Sunflower

- Zinnia

Topped by a Head

Topped by a Head

Variations on a ThemeDandelion – all rays

Variations on a ThemeDandelion – all rays

Pussytoes – all disk

Variations on a ThemeDandelion – all rays Cornflower – All

Disk/outer ones larger Pussytoes – all disk

“Doubled” Heads

Single (“Old-Fashioned”) Zinnia

“Doubled” Heads

Single (“Old-Fashioned”) Zinnia Double Zinnia

Another Double

Single Marigold Double Marigold

Marigold – Tagetes - native to Mexico

Daisy – Inspiration for “Big Orange”

Daisy – Inspiration for “Big Orange”

UT Uniform Color – traces origin to center of daisy heads

Daisy – Inspiration for “Big Orange”

Shasta Daisy – tetraploid selection of Luther Burbank

UT Uniform Color – traces origin to center of daisy heads

Polyploidy – Breeding Tool

Daylilies – Hemerocallis fulva

Diploid Tetraploid

Polyploidy: >2 sets of

chromosomes

1. Determinate organs will be larger

2. Stabilizes (and sometimes makes fertile) hybrids

3. Odd polyploids often sterile:

- no messy seeds

- no need to “deadhead”

Flowers - Variations

Showy structure is not part of flower

bract

dogwood

poinsettia

More Flower Variations

More Flower Variations“doubled” flowers – stamen primordia petals

Pink Carnation

Araceae – the Houseplant FamilyMany Aroids – tropical epiphytes – habitat similar to house/apartment

Spathiphyllum – the Mall PlantNote: inflorescence is spathe + spadix

Amorphophallus – a Giant Aroid

1.37 m tall

Amorphophallus titanum

Geneticist Huge de Vries, one of the rediscoverers of Mendel’s Laws, provides scale for an inflorescence of the “Voodoo Plant”

Amorphophallus – a Giant Aroid

1.37 m tall

An Aroid Gallery

How Dumb Cane Got Its Name

How Dumb Cane Got Its Name

Calcium oxalate – characteristic crystalline inclusions (raphides) in Araceae extreme irritation of mucous membranes

Can lead to fatal swelling of passages to lungs

Commonly Ingested AroidsFrom List of “Top 20 Ingested Plants” Reported to Poison Control

Centers in U.S.:

2. Philodendron

4. Spathiphyllum

6. Dieffenbachia

10. Epipremnum (Pothos)

Treatment: Symptomatic and Supportive – remove residue from mouth; provide liquids; monitor breathing (major danger is suffocation is swelling is severe)

Invasive Plants – The Dark Side of Ornamentals

Invasive Plants = “Biological Pollution”

“Rule of 10’s”:

Invasive Plants – The Dark Side of Ornamentals

Invasive Plants = “Biological Pollution”

“Rule of 10’s”:

For every 10 plants introduced, 1 will become established

Invasive Plants – The Dark Side of Ornamentals

Invasive Plants = “Biological Pollution”

“Rule of 10’s”:

For every 10 plants introduced, 1 will become established

For every 10 established, 1 will become invasive

1 in 100 introductions becomes invasive

Invasive Plants – The Dark Side of Ornamentals

Invasive Plants = “Biological Pollution”

“Rule of 10’s”:

For every 10 plants introduced, 1 will become established

For every 10 established, 1 will become invasive

1 in 100 introductions becomes invasive

Often a long lag time, introduction problematic invader

“First it sleeps, then it creeps, then it leaps …”

Invasive Plants – The Dark Side of Ornamentals

Invasive Plants = “Biological Pollution”

“Rule of 10’s”:

For every 10 plants introduced, 1 will become established

For every 10 established, 1 will become invasive

1 in 100 introductions becomes invasive

Often a long lag time, introduction problematic invader

How to Predict Invasiveness?

- only clear guide, if invasive in other areas

Dandelion - Invader

Taraxacum officinale (“of the shops”)

Dandelion - Invader

Taraxacum officinale (“of the shops”)

Dandelion (“dents du lion” = lion’s tooth, from leaves)

Dandelion - Invader

Taraxacum officinale (“of the shops”)

Dandelion (“dents du lion” = lion’s tooth, from leaves)

Asteraceae – all ray flowers

Introduced by Pilgrims – used as spring potherb

Dandelion - Invader

Taraxacum officinale (“of the shops”)

Dandelion (“dents du lion” = lion’s tooth, from leaves)

Asteraceae – all ray flowers

Introduced by Pilgrims – used as spring potherb

Flowers – produce abundant nectar sugar source to produce wine

Dandelion - Invader

Taraxacum officinale (“of the shops”)

Dandelion (“dents du lion” = lion’s tooth, from leaves)

Asteraceae – all ray flowers

Introduced by Pilgrims – used as spring potherb

Flowers – produce abundant nectar sugar source to produce wine

Apomictic – seeds produced without fertilization clones of parent

Will mature its seed even if uprooted

Tennessee Invaders

TN-EPPC (Tennessee Exotic Pest Plant Council) – List

Trees: Mimosa (Albizzia); Princess Tree (Paulownia); Tree-of-Heaven (Ailanthus)

Shrubs: Autumn Olive (Eleagnus); Bush Honeysuckles (Lonicera); Japanese Barberry (Berberis); Multiflora Rose (Rosa); Privet (Ligustrum)

Herbs: Purple loosestrife (Lythrum); others

Vines: Euonymus; Japanese honeysuckle (Lonicera); Japanese wisteria; Kudzu (Peuraria); Oriental Bittersweet (Celastrus)

Native Plants – A Great Resource

Answer to Invaders = use native plants

See Box 17.2, p. 429 Wildscaping

Opportunity: provide plants for revegetation, environmental restoration projects

Thursday, Genetically Modified (GM) Plants