1. Lab #6B
Angiosperms

2. Flowers
structure of a flower – 4 rings of modified leaves called flower organs:
1. sepals
2. petals
3. stamens
4. carpels
Stamen
Filament
Anther
Stigma
Carpel
Style
Ovary
Petal
Receptacle
Ovule
Sepal
Stigma
Style
Anther
Filament
Sepal

4. Perfect flowers male and female on same plant lilies dandelions roses
virtually every fruit and vegetable plant in North America
tomatoes
dandelion
african violet
apple blossom

5. Imperfect flowers
male and female reproductive parts on separate flowers
but may be on the same plant
staminate flowers
carpellate flowers
staminate flowers

6. Inflorescences
inflorescences = group of cluster of flowers arranged on a stem that is comprised of a main branch or a complicated arrangement of branches
several types
raceme - unbranched main axis, flowers attached by a pedicel
spike – unbranched main axis, directly attached flowers
panicle – branched main axis
corymb
head (flower head) – also known as a composite flower

7. Composite flowers
composite flowers = clusters of many small flowers called florets – each of which is a full flower
chicory, dandelion, chrysanthemum, yarrow, coreopsis, sunflower, dahlia, zinnia, goldenrod, aster, lettuce, thistle and Black-eyed Susan.
composites are miniaturized flowers
numerous flowers packed onto a platform called a receptacle,
so the sunflower is actually a collection of hundreds of flowers!
two kinds of flowers: disk flowers and ray flowers
disc flowers – center of the receptacle
ray flowers – surround the disc flowers (look like petals)
disc flowers
ray flowers

8. Flower ovules Lilium ovary with ovules Ovary with ovule

9. Ovules
Ovule
Ovules

10. Anthers

11. Fruit
composed of an outer wall = pericarp and the inner placenta with seeds
pericarp is made up of an exocarp, a mesocarp and an endocarp
e.g. apple – skin = exocarp; flesh = mesocarp; paper part in the center = endocarp; seeds
classified as: simple, multiple or aggregate
simple – one carpel or several fused carpels form the fruit
e.g apple
multiple – more than one flower with female parts
aggregate – number of separate carpels form the fruit

12. Fruits – dichotomous tree
first division – fleshy or dry
I. Fleshy
A. simple (from a single ovary) or B. complex (from more than one ovary)
A. simple- drupe (hard endocarp = cherry, olive, coconut), berry (fleshy endocarp = tomato, grape, peppers, cucumbers), pome (apples, pears)
B. complex – aggregate (fruit from many carpels on a single flower = strawberry, raspberry), multiple (fruit from carpels of many flowers fused together = pineapple, corn)
II. Dry
A. fruits that split open at maturity (more than one seed) or B. fruits that do not split (one seed)
A. fruits that split – along one seam (peas, beans and peanuts), along multiple seams (okra, lilies, poppies)
B. fruits that don’t split – hard pericarp (acorns, chestnut), thin pericarp and winged (maples, ash, elm), thin pericarp no wings (sunflowers, cereal grains, grasses)

13. Placentation
ovules develop from the placenta and are attached to the ovary wall until maturation into seeds
arrangement of the placenta = placentation
parietal – ovules on the outer ovary wall or extensions of it
free central – ovules along a central column or axis
axile – ovules along a central axis which is connected to the ovary wall

14. Placentation
Parietal placentation
Axile placentation