Sex in Your Garden

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Sex in Your Garden

• Ronald C. Smith, Ph.D.
• North Dakota State University
• Extension Horticulturist Turfgrass Specialist
• Power-point material taken from
• Sex in Your Garden, written by Angela Overy
• Created by Andrea Carlson

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All About Sex

• Male femaleswitch??!!
• Happens everyday!
• Same organs as humans
• One goalreproduce
• Need others to perform for them
• From male to female plants

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Natural Selection

• To accommodate all the worlds pollinators, from
  the most selective flowers to the most
  undiscriminating slug, the sex life of flowers is
  more varied than ever before, and more ingenious
  than most humans imagine

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The Sexual Organs
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Male Parts

• Stamens
• Male parts of flower
• Look like bunch of stalks
• Different families have different numbers
• Separate or together
• Filaments
• Stamen stalk
• Hold pollen
• Often slender, springy
• Anthers
• Attached to tip of filament
• Often yellow can be any color
• Various shapes and pollen dispersal

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Pollen Grains
Daisy, magnified
Iris, magnified
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Making it Obvious!!!
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Female Parts

• Center of flower
• Carpel individual unit
• Pistil several carpels
• Stigma
• Top of pistil, often stick out
• Catches pollen grains
• Retains until IDs
• Ready Increase scent, become dewy sticky

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Ovaries

• Where ovules (eggs) may be fertilized develop
• Inside are eggs (one)
• Arranged in various patterns on placental tissue
• Kept moist well-nourishedwaiting
• One pollen grain to fertilize each ovule (seed)

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Ovules

• Plant puts energy into seed production
• Annual one summer to complete life cycle
• If unfertilized, will not develop further
• Fertilized ovules grow into seeds/new plant

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Bisexual Flowers

• Have both male female parts
• Very realistic flexible arrangement
• Self-fertilization is avoided if stamens
  pistils in single flower are sexually active at
  different times
• Males active first
• Mints, Penstemons, Evening Primroses,
  Honeysuckles
• Females active first (or until pollinated)
• Magnolias, Water Liles, Pasque Flowers,
  Dutchmans Pipe
• Making it impossible
• Chemical physical barriers

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Selfing

• Saves energy
• Little flowersunpopular!
• Evolution poor conditions/no carriers
• Self-pollinate as last resort
• Devoted only one pollinator or will
  self-pollinate
• Promiscuous any pollinator will do

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Sex Appeal

• The ultimate advertising campaign
• As plants reach puberty they advertise their
  health, size and species while growing into a
  recognizable shape

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Attracting Attention in a Competitive Field
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Advertising with Color

• Anenomes as perceived by

Humans
Bees
Beetles
Hummingbirds
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Bee Guides

• Also called nectar or honey guides
• Colored stripes, spots and markings on petals
• Help pollinators find flowers quickly
• Fierce competition to woo flighty pollinators
• Plants use visual, tactile, fragrant aids to gain
  max. advertising impact

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Targeted Designs

• Look Here!

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Advertising with Scents

• After color, scent is the next most important
  advertisement
• Most insects have an exquisite sense of smell
• Scent costs flowers energy

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Advertising with Shapes
Common Flower Shapes that Attract Pollinators
Landing platform for bees
Open sun warmed bowls
Selective entrances for long beaks tongues
Landing platform for bees, flies, beetles, and
butterflies
Shelter from rain predators
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Bowl-Shaped Flowers

• Can be easily seen from the air
• Bowl provides shelter
• Extra heat inside bowl can speed up seed
  production
• Popular for short-tongued insects

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Landing Platforms

• Bees pollinate more flowers than other insects
• Landing sites where they can put their feet down
  are very popular
• Area has to be sturdy

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Conceal or Reveal!?

• Some flowers are structured so that insects can
  access food easily others hide all they have to
  offer!

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Barely Concealed

• Some designed for certain pollinators
• Delphinium--bees, below

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Hairy Flowers

• Hair/hairiness play part in attractiveness
• Hairs
• Commonly defensive protective
• Memorable distinctive
• Trap pollen
• Point pollinator toward nectar

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Sex Through the Seasons

• Maturing early gets a jump on the competition..
• First to bloom in spring and last in winter

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Copying a Successful Competitor

• Advertising campaigns are costly companies may
  copy products to sell
• Plants may mimic shape, color, size, smell

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Great Bribes

• Once advertising has grabbed pollinators
  attention, plant needs to coax towards a more
  intimate relationship
• Plant needs pollen, so needs to offer goods in
  exchange
• Food, shelter, home-building materials

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Nectar

• Nectar
• Food bribe
• Liquid containing sugars, amino acids, vitamins,
  minerals
• Composition varies with plant, time of day,
  weather, age of flower, pollinator
• Quick to drink, easily absorbed into system,
  provides almost instant energy

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Pollen

• Pollen
• More sustaining than nectar for visitors
• Excellent source of protein
• Smaller amounts of sugars, amino acids, vitamins,
  minerals, anti-oxidants, fat or oil
• Carry plants male genes
• Bees are major consumers, but others enjoy

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Pain Shame

• Plants with a criminal aspect!
• Lure insects to their flowers then trap them,
  releasing them at their convenience
• Mouse Plant (Arisarum proboscideum), above right
• Fungus-like smell
• Resembles mice with stinking, long, bare tails
• Insects may be allowed to leave!
• Jack-In-The-Pulpit (Arisaema triphyllum), above
  left
• Both male female parts
• Gnats gather at male parts, fall into the
  flower, get covered with pollen, escape through
  special hole
• Female body parts gather gnats covered with
  pollen, only do not let them escape!

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Murder in the First!

• Plants that live in wet, boggy areas may find it
  difficult to gather nutrients through their roots
• Thus these plants trap insects for pollination
  and nutrients, particularly proteins
• Water Lilies (Nymphaea), top 2 pictures
• Fragrance attracts a host of insects
• Insects may drown in nectar deep in the flower
• Butterfly Flower (Asclepias tuberosa), bottom
• Traps weak unwary insects

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OrchidsFraudulent Advertisements

• Thousands of orchid species have evolved to fool,
  cloaking their sexual urgency with sophisticated
  shapes techniques to ensure pollination
• May mimic female insect traits
• odors, patterns, colors, textures

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Busy Bees

• Honeybees
• Live in a ridged, complex society containing
  50,000 bees
• Colony usually has 1 adult queen who lays the
  eggs while being waited on by worker bees,
  usually virgin female workers
• Male bees (drones) only job is to mate with the
  queen
• Bumblebees
• Excellent pollinators due to large body size,
  strength, long tongues
• Can live at higher altitudes and cooler temps
  than other bees
• Live in small colonies (400) do not dance to
  communicate
• Female does some work
• Other Wild Bees
• Life cycle is synchronized with their flowers

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Wasps

• Not nearly as useful as bees
• Bodies have less, finer hair for pollen to stick
  to
• In cooler climates, wasps are not around to
  pollinate spring flowers
• Eat a wide range of food
• Bee larvae, spiders, fruit, flowers
• Favor some of the dingier colored flowers

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Butterflies

• Pollinate flowers with long, thin tongues (as
  long as their bodies)
• Can see colors, have excellent sense of smell,
  gather info with pair of antennae
• Prefer flat-topped flowers in an open location

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Sweet Fly-Flowers

• Some flies feed on both pollen nectar
• Flowers are usually small, flat surfaced, with
  visible nectar, pastel or light green

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Beetles

• Due to hard, protective exterior, beetles can
  stay in flowers for long periods of time, eating,
  resting, mating
• Most cannot perceive color, so likely to visit
  white flowers
• Some eat decaying matter, pollen, nectar

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Hummingbirds

• Feed on nectar protein-rich insects to fuel
  extremely high metabolic rate
• Consume ½ of weight in food daily
• Feed in flight flowers have no scent, no landing
  area, face outward

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Bats

• Cacti flowers of hot, dry deserts of SW U.S.
• Disperse pollen seeds
• Fly feed at night have poor eyesight color
  sense, so rely on acute sense of smell

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Having it Both Ways

• Some plants are partly wind insect pollinated
• May be still evolving

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Blown Over

• Most pollen is blown a short distance--inches or
  yards
• Some is carried on air currents up to high
  altitudes, even in the jet stream, traveling
  thousands of miles
• At high altitudes, ultra-violet light can damage
  pollen
• Pollen is estimated to be on every square yard of
  the earth has been found in the middle of the
  Atlantic Ocean

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Human Intervention

• In labs farms, gene manipulation artificial
  insemination has become common
• Driven by consumers tastes fashions
• Hybrids
• Plants resulting from pollinating 2 distinctly
  different members of the same species
• Long-term investment8 years
• Grown indoors in controlled conditions with no
  insects
• Hand-pollinated

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Family Farewell

• Most common way to create another plant is sexual
  propagationseeds, followed by grafting,
  cuttings, layering, dividing
• Seeds
• Distributors of the plants genes
• Effective dispersal is key to plant survival
  evolution
• Moved by wind, water, insects, animals

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Questions?