Pollination

pollination

Process by which pollen is transferred in the sexual reproduction of plants

wind, water, and animals

pollen vectors

agents that move pollen from an anther to a stigma

ex. insects and vertebrates

Why pollinators visit flowers

to obtain a reward such as pollen or nectar

Co-evolution has resulted in

much of the diversity of flowering plants

some species are very specific co-dependent relationships

pollination syndromes

suites of floral traits that have evolved in response to natural selection imposed by different pollen vectors

traits of pollination syndromes

flower shape, size, color, odor, reward type and amount, nectar composition, timing of flowering, etc.

biotic pollination syndromes

Beetle, Fly, Bee, Butterfly, Moth, and Vertebrate

Abiotic pollination syndromes

wind and water

beetle pollination

visit flowers in order to eat the pollen

they were probably the first insect pollinators of flowering plants

traits of beetle pollinated flowers

Flowers cream or dull red colored with a strong sweet odor; flattened or dish shaped; traps

"mess and soil" pollinators

Ex. Magnolias and aroids

fly pollination

Some flies visit carrion-flowers (fecal like odor) in order to lay eggs; such flowers do not have a pleasant odor

traits of carrion fly flowers

look like rotting flesh or fecal matter

Foul odors (fetid) and look like decaying organic matter

No nectar reward

Sometimes elaborate floral morphology to hold flies in a trap while flowers proceed through development ex. protogynous or protandrous

"mess and soil" pollination

example of carrion fly flowers

araceae, giant 6-7 feet, smells of rotting meat, thermogenic warms to around body temp

Wind pollination

some flowers have reverted to wind pollination; stamens and stigmas are large and exposed to the wind

ex. grass, cattail, oak

wind pollination characteristics

Reduced perianth

Imperfect flowers - monoecy or dioecy

Exerted stamens - light, dry, thin-walled pollen

Enlarged stigmatic surface

Do not possess a scent or produce nectar

The syndrome has evolved independently many times in different clades

bee pollination

There are many kinds; seek pollen, nectar or both; flowers differ to match

bee types

solitary or colonial

ex. small bees, small and large carpenter bees, honeybees

traits of bee pollinated flowers

Flowers yellow, blue, purple; often with UV nectar guides

Often bilateral symmetry; landing platforms

Nectaries (produce nectar) present

Small amount of pollen produced (less needed, saved energy)

Specific placement of pollen

Fragrant (perfumes; pheromones)

Sometimes extreme cases of co-evolution and adaptation

floral tubes and bees

Corolla tube length can limit access to the nectaries to a restricted range of bee visitors, due to length of bee type proboscis

ex. in snapdragons bees push open to get to nectar and pollen gets on back

butterfly and moth pollination

Lepidoptera have long narrow mouth parts; flowers have corolla tubes that are long and narrow

less efficient that bees

traits of butterfly pollinated flowers

attracted to bee flowers or similar to bee flowers but with much longer floral tubes

Flowers blue, pink, yellow, or orange; sometimes with nectar guides

Narrow floral tube; horizontally or vertically oriented

Diurnal (during the day) nectar production

Diurnally receptive stigma

Pleasant odor

"mess and soil" pollen placement or very specific pollen placement

example of butterfly flowers

milkweeds, have butterfly stirrups

traits of moth pollinated flowers

attracted to flowers similar to butterfly flowers, but:

Flowers cream colored

Nocturnal nectar production

Nocturnally receptive stigma

Sometimes very long more or less horizontally-oriented floral tube

strong sweet odor (too sweet!)

"mess and soil" pollen placement or very specific

example of moth flowers

"mess and soil" pollination, ex. clematis

can have very long floral tubes due to really long proboscis, ex. evening-primrose

can be robbed by bees where they chew through the flowers, ex. Azalea and rhododendron

bird pollination

some hover, some perch; flowers evolved to match; birds are attracted to bright colors and lots of nectar; no odor

need lots of nectar only used where insects are not as common

hovering birds flower traits

for hummingbirds and sunbirds

Flowers bright red, orange or yellow

Long narrow horizontally-oriented floral tube

sticky pollen

lots of sugar-rich nectar, "additives"- proteins, salts, AA

no odour

"mess and soil" or specific pollen placement

diurnal (during day)

perching birds flower traits

for parrots

bright colors

sturdy perch for bird to land on

lots of pollen and nectar

"mess and soil" pollen placement

diurnal

examples of hummingbird flowers

bird-feeder

pollen placement on the top of the head is also common, ex. Christmas cactus

common, late summer, wet soil plant, ex. cardinal flower

examples of perching bird flowers

Sturdy parts for the birds to stand on while foraging for nectar

Woody calyx forms the perch

ex. banana

bat pollination

Nocturnal, easily "echo-locatable"- pendant flowers/inflorescence

ex. century plant and banana

traits of bat pollinated flowers

Flowers dull red or cream colored

Sturdy floral parts; often bell shaped

Lots of pollen and/or nectar

Strong sweet/musty odor

Nocturnal blooming

"Echo-locatable" positioning of flowers on stem or pendant inflorescences

"mess and soil" pollen placement either on the head or entire front of the body

Bats are messy eaters!

examples of bat flowers

Ball of flowers on long hanging stalk making flowers easily "echo-locatable"

ex. Parkia

Mice and opossum pollination

Other mammals are also utilized as pollinators....but not very often

ex. opossum on Banksia, rock mous on Protea

traits of non-flying mammal pollinated flowers

Flowers dull-colored

Large and sturdy, or are grouped together as multi-flowered inflorescences

Flowers lay on the ground

Nocturnal blooming

Strong pungent odor

Lots of sugar-rich nectar

Lots of pollen

"mess and soil" pollen placement