Lecture 16. Angiosperms1. Abominable mystery- A sudden rise of the relatively modern flower in the fossil record.2. Nine clades of angiospermsA. Archaefructus- Extinct but successful species.- No woody part; herbaceous plants- Aquatic shrub- Fruits- Male and female reproductive parts-> pre-flower: no pedal, no sepal -> no attract pollinator; rely on water to transport pollen. B. Amborella- Most ancient- Small shrub or tree- Woody structure- Small flower- Abominable mystery- Hermaphroditic: but only one sex develop fully -> functional dioecious.*Hermaphroditic: male and female within a single flower.*Monoecious: male and female within a single plant.*Dioecious: male and female separated in a given individual.C. Nymphaeales- Extended leaf and flower stems allow for floration. - Strong: can carry organisms on top - Umbrella- No vessel cell; only angiosperm: live in water- Leaf is the lily pad and it photosynthesize- Roots and stem- Stomata (open to get air and water comes out) are exclusively on top of the lily pad.D. Austrobaileyales- Relatively recently added group- Woody plants- Live in tropical area- Not all evergreen leaves are conifers; Evergreen means it doesn’t lose its leaves.E. Chloranthaceae- Several dozen species of woody plants - Tropics, sub-tropics- Not well-known groupF. Ceratophyllum (aquarium)- Float on water - Provide protection to fish babies- Developing snail- High oxygen productionG. Magnoliids- Economically important: food, drug, timber, perfume- Nutmeg, magnolias, avocado, cinnamon, black pepper- Trimerous flowers: flowers parts in groups of 3 (3 sepals, 3 petals, 3 stigmas)- Broad leaves with branching veinsH. Eudicots- Contains many familiar flowers; sun flower, roses, violets, cabbage, maple, butter cups, peas)- Four or five merous flowers: parts in 4~5 flower parts. - Leaves are similar to magnoliids: rose-like leaves: broad leaves with branching veins.I. Monocots- corn, wheat, rice, palms, bananas, ginger, onions, - Iris, orchids, tuplips, garics- Trimerous flower, but leaves with parallel veins.3. Pollination- Flower mating- Pollen contacts stigma- Up to formation pollen tube and embryo, endosperm4. Fertilization- Formation of 2N zygotes.5. Pollination syndrome: suits of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic (wind and water), or biotic (birds, bees, flies, and so forth). These traits include flower shape, size, color, odor, reward type, and amount nectar composition, timing of flowering, etc.A. Abiotica. Watero most ancestral form of pollinationo water pollinating plants must have pollens that float on watero Pollen must be impervious to watero Close to waterb. Windo Probably the 1st way primitive land plant used.o Small greenish, odorless flowers.o Rarely pollen goes less than 100m -> close to each other.o Ex) tassel: Petals are extremely reduced so wind can blowthe pollen. .B. Biotica. Beetle (insect)o The 1st insect pollinator.o The flowers are usually large, green (or white: they don’t see colors), and odorous (sensitive to smells).o The flowers are flat or dish-shaped so that beetles can walk around.b. Short-tongued bees (flies)o Tend to go wide open of species.o Walk around on the flowers that they pollinate.c. Long-tongued bees (bumble bees)o Can reach down narrow yubular flowerso The flowers are often blue-colored: bees can’t see red color.o The flowers have complex placement to ensure pollinationso they don’t self-cross.o The flowers have stripes or lines of dots on their flowers that indicate where the nectar is. (called nectar guide)o Mechanism isolation: the pollen carried by bees can be only collected by complementary structured flowers.d. Butterfly (not well to hover and fly)o The flowers tend to be larger and showier.o Scentedo The flowers can be tubular or flat.o The flowers are often pink.o The flowers have structure for butterfly to stand because they can’t hover.o The flowers are odorous.o Butterflies can’t digest pollen, whereas bees can. Therefore, flowers offer more nectar to butterflies.e. Moth (hover and hand well)o Flowers don’t need landing platform.o The flowers tend to be white and opening at night/dawn: moths move around in night or early morning.o The flowers tend to be showy and large.o The flowers tend to have tubular structure to hide nectar: need long tongue. o The flowers usually have sweet scent during evening/ night/ early morning. o A lot of nectars are produced for moth to eat: moth need energy to fly.f. Hummingbird-> tubular red flower with nectar.o Narrow beak -> tubular o Eat nectars, but they don’t have as much amino acids, so the hummingbirds eat insects.o The flowers tend to be red/orange and odorless.g. Bat- The flowers tend to be large, because bats are big.- The flowers tend to be showy; white/ light color and strong odorous and opened at night.- The flowers usually are bell-shaped and pendant (hanging down)- The flowers often offer a lot of nectar- Very open to access bat’s head in.6. Coevolution- Occurs when two species evolve in concert: they evolved in response to each other.- Happens when pollinators and flowers help each other or opposeone another.- Flowers (prey species) either develop to attract pollinator ot avoid pollinator.- Pollinators (predators) develop to find flowers- The relationship between flowers and their pollinators has led to increased number of floral plants.* Tubular flowers often have depths that exactly match the tongue or beaklength of their pollinators. -> Natural Selection.7. The example of Aristolochia (trap flowers)- Magnoliids- Have long trumpet shaped opening- The reverse oriented hairs: flies can get into the flower but can’t leave until the stigma receive pollen that fly brought with and flies get the trap flowers’ pollen. It ensures exchange of
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