1. Flower Structure Jason Gehrke 2014C, 2014D, 2022D

2. 4 Influential Factors  Plant Hormones  Daylength  Nitrogen  Temperature

3. Plant hormones  http://waynesword.palomar.edu/trmar98.htm  Trigger the conversion of the meristem from vegetative to floral  Initiates formation of new parts Petals Sepals Stamen Pistils

4. Complete/Incomplete Flowers  Complete Flowers Contain four principal parts Contain four principal parts SepalsSepals PetalsPetals StamenStamen PistilPistil  Incomplete Flowers Missing one of the four principal parts Missing one of the four principal parts

5. Daylength  http://waynesword.palomar.edu/trmar98.htm  Length of night will initiate flowering  Two types of lengths Long Short

6. Long Day Plants  Plants flower with decrease in night length  Days get longer  Examples Wheat Wheat Oats Oats barley barley  http://news.minnesota.publicradio.org/features/2003 /04/24_gundersond_gmwheat/

7. Short Day Plants  Plants flower with increase in night length  Days get shorter  Examples Soybeans Soybeans Corn Corn Sorghum Sorghum  http://www.tiscali.co.uk/reference/encyclopaedia/hut chinson/m0014425.html

8. Calendar of Flowering

9. Nitrogen  Deficiency will cause poor flower formation

10. Temperature  High temperatures will kill flowers (wilt)  Cold temperatures will also kill the flowers  http://www.wiretapestry.com/photoalbum/2- 1batch/deadflowers.jpg

11. Flower Structure  Sepals- modified leaves often green and small  Petals- large and colorful, aid in attracting insects and other pollinators  http://waynesword.palomar.edu/trmar98.htm

12. Flower Structure  http://waynesword.palomar.edu/trmar98.htm  Stamen- Male reproductive organs Anther- produces pollen Filament- stalk that holds anther to flower  Pistil Stigma- Sticky top of pistil that receives pollen Style- tube connects stigma to ovary Ovary base of the pistil, holds the eggs

13. Corn Different from the Norm  Tassel- male floral structure hold pollen  Ear- female floral structure  Silt- elongated styles to catch pollen Pictures to the right: http://www.hort.purdue.edu/ext/senior/vegetabl/corn3.htm

14. Pollination  http://www.biologie.uni-hamburg.de/b-online/e02/02d.htm  Transfer of pollen from the anthers to the stamen

15. Fertilization  Union of the sperm and the egg  Two sperm cells One to fertilize egg One to fertilize embryo