Presentation on theme: "HortBotany Lesson Plan #9"— Presentation transcript:
1 HortBotany Lesson Plan #9 FlowersHortBotanyLesson Plan #9
2 Flowers: A Marvelous Innovation Flowering plants first appeared around 140 million years ago (Upper Jurassic).Oldest flower fossil is 125 million years old.The dominant forms of plant life were gymnosperms, cycads, and ferns.
3 TodayFlowering plants (Angiosperms) are now the dominant form of plant life over most of the earth’s land surface. Ferns are rarely dominant and gymnosperms are dominant only in cold, or seasonally cold locations. Cycads are hanging on by a thread. Why have flowering plants been so successful?
4 Angiosperm FlowersOvaries protect ovules and developing seeds; mature into fruits that promote seed dispersalFloral structure encourages pollinator fidelity; nectar and pollen to reward pollinatorsFast reproductive cycle compared to gymnosperms
5 Structure of flowersFlowers are composed of four whorls. From the outside in, they are:Calyx (sepals)Corolla (petals)Androecium (stamens)Gynoecium (pistils)
6 Calyx Outermost whorl Usually green Protects developing flower Made up of SEPALSSepals free or not
7 SepalsUsually green; leaflike structures that protect the flower, as it forms and emerges.
10 Corolla Is usually colorful and showy Attracts pollinators Guides pollinatorsIs composed of petalsPetals may be united or separate
11 Petals Located just inside the sepals Leaf-like and often very colorful
12 The collection of petals on a flower CorollaThe collection of petals on a flower
13 PerianthThe sepals and the petals of a flower. (Not the reproductive parts.)
14 HIPPEASTRUM 'MARMADUKE’ TepalsWhen there is no clear distinction between the sepals and the petals...they are called “tepals”.HIPPEASTRUM 'MARMADUKE’
15 Androecium Is composed of stamens Stamens have filaments and anthers Pollen is produced in anthersStamens can be free or united
16 Stamens Male reproductive parts of a flower Arranged around the female parts
17 AntherPart of the stamenProduces and holds pollen
18 Stalk that holds up the anther FilamentStalk that holds up the anther
19 Gynoecium Is composed of pistils A pistil is composed of an ovary, style, and stigma.
20 Pistil = 1 or more carpels Each theoretical leaf unit is termed a carpelA pea pod is a mature pistil made up of 1 carpelPistils with 2 style branches and/or chambers in the ovary are said to have 2 carpelsPistils with 3 style branches and/or chambers are said to have 3 carpels etc.
21 Stigma Found at the end of the pistil Has a sticky surface to catch pollen
23 OvaryPart of the pistil that contains the ovules
24 OvuleThe part of the flower in which the eggs are produced and seeds develop
25 Ovary Position I. Above the calyx and corolla (ovary superior) II. Ovary partially inferiorIII. Below the calyx and corolla (ovary inferior)Ovary position: I superior II partially-inferior III inferior.a androecium g gynoecium p petals s sepals r receptacle.
26 HypanthiumIf the corolla and calyx are attached to a cup or tube that is then attached to the receptacle, the cup or tube is called a hypanthium.
27 ReceptacleThe top floral whorls are attached to the receptacle – the tissue where the stalk to the flower changes to being part of the flower
28 Pedicels Flowers are borne on pedicels Think of a pedicel as the stalk to a flower
29 Attracting Pollinators To survive, species must reproducePollination is the first major step in the reproduction of seed plants like gymnosperms and angiospermsFlowers persuade animals to serve as pollinators, preferably faithful pollinatorsTo get the right pollen, flowers need to be memorable so …
30 Start thinking like a pollinator Is there a reward?How can I find another like this one?SymmetryColor patternOdorWill it be safe for me?Corolla – united or separate petalsCorolla more important than calyx – why?Can I reach the reward and is it adequate?nectaries and androecium