Plant Classes and Parts

1. Plant Classes and Parts Basic Plant Science AFNR-BAS-13: Explain and demonstrate basic plant science principles including plant health, growth and reproduction.

2. Uses of Plants • Plants provide for the three basic human needs: • food: fruits, vegetables, grains, nuts, etc. • clothing: cotton, linen, wool, leather (plants feed the animals that grow the wool and leather) • shelter: lumber and other wood products www.OneLessThing.net

3. Uses of Plants • direct source: the plant or plant products are used by humans • fruits, nuts, vegetables, cotton • indirect source: humans use the animal and animal products that feed on plants and plant products • beef, leather, chicken, wool www.OneLessThing.net

4. Uses of Plants • Plants are also used by humans for ornamental and aesthetic reasons to provide comfort or beauty. • landscaping (flowers, shrubs, trees, turf) • ornamental horticulture and floral design (house plants, cut flowers • forestry and outdoor recreation (wildlife habitat, hiking, hunting) www.OneLessThing.net

5. Major Groups of Plants • gymnosperms: • means “naked seed” in Greek • plants that produce seeds not protected by fruit • examples: pines, firs, spruces, redwoods, ginkgo www.OneLessThing.net

6. Major Groups of Plants • angiosperms: • in Greek means “covered seed” or “enclosed seed” • plants that flower and produce seeds protected by fruit or pods • examples: apples, peaches, pecans, soybeans www.OneLessThing.net

7. Major Groups of Plants • There are two classes of angiosperms with distinct characteristics. • cotyledon: an embryonic leaf which become the seed leaf • monocotyledons (a.k.a. monocots); “mono-” - means “one” • dicotyledons (a.k.a. dicots); “di-” means “two” www.OneLessThing.net

8. Major Groups of Plants • monocotyledons (a.k.a. monocots) • seeds have one cotyledon therefore the seedlings have one seed leaf • the vascular bundles are scattered • the leaves have parallel veins • flower parts are in multiples of three www.OneLessThing.net

9. Major Groups of Plants • dicotyledons (a.k.a. dicots) • seeds have two cotyledons therefore the seedlings have two seed leaves • the vascular bundles are arranged in a circle • the leaves have netted veins • flower parts are in multiples of four or five www.OneLessThing.net

10. Taxonomy (Naming Plants) • scientific names are in Latin and printed in italics • common names can be confusing because different areas call plants by different names • binomial nomenclature • two-name system • first name is the genus • second name is the species • species can be further subdivided into varieties www.OneLessThing.net

11. Plant Life Cycles • Annuals: plants that complete their life cycle in one year (or one season) • examples: marigolds, pansies, petunias, melons, beans, squash (and many other flowers, crops, and weeds) www.OneLessThing.net

12. Plant Life Cycles • Biennials: plants that complete their life cycle in two growing seasons • grows vegetative structures (roots, stems, leaves) in the first year and then after a period of dormancy during cold months, it will produce flowers and seeds before dying • examples: carrot, parsley, onion, cabbage, hollyhock, Black-eyed Susan www.OneLessThing.net

13. Plant Life Cycles • Perennials: plants that produce for more than two years or growing seasons • may die back during the winter months and then return from their rootstock • examples: azalea, alfalfa, pine trees, maple trees, fruit and nut trees, blueberries • There are two classes of perennials. • herbaceous: plants that have soft stems that are killed by frost • woody: plants with hardy stems that can survive winter frost www.OneLessThing.net

14. Plant Processes • photosynthesis: the chemical process converting sunlight into energy and food for the plant • respiration: the process of plants using stored energy • transpiration: the movement and loss of water through evaporation www.OneLessThing.net

15. Plant Parts • Roots: • anchor the plant • absorb water and minerals • store manufactured food • primary root: the single main root • secondary roots: small roots that branch off the main root • root hairs: many tiny roots that increase the surface area of the root for absorption • root cap: protects the growing tip of roots www.OneLessThing.net

16. Plant Parts • Types of Roots: • tap root: root system with one thick main root • fibrous roots: system with many small roots • adventitious roots: grow from the stem or leaf of a plant • example: corn has roots above ground to prop up the stalk www.OneLessThing.net

17. Plant Parts • Stems: • support the leaves, flowers, and fruit • conduct water, minerals, and food • store food and water • produce new stem tissues www.OneLessThing.net

18. Plant Parts • Two types of conductive tissues in the stem: • xylem: transports water and minerals from the roots • phloem: transports food from the leaves • both are created by the cambium which becomes growth rings in trees • the xylem and phloem are arranged in a ring in dicots and scattered in moncots www.OneLessThing.net

19. Plant Parts • Leaves: • produce food for the plant through photosynthesis • epidermis: protective layer of cells • cuticle: waxy coating that prevents water loss • stomata: pore-like openings on the underside of the leaf that allow gas exchange • guard cells: control the opening and closing of the stomata • mesophyll: where photosynthesis takes place; made up of palisade layer and the spongy layer • veins: contain xylem and phloem and transport water and nutrients www.OneLessThing.net

20. Plant Parts • Flowers: • purpose of flowers is to reproduce through the production of seeds • sepals: the outermost part of a flower (usually green) that protects the unopened flower and supports the petals when it blooms • as a whole all the sepals are called the calyx • petals: attract insects and birds for pollination; usually conspicuously colored www.OneLessThing.net

21. Plant Parts • Flowers: • stamen: the male part of the flower • anther: produces the pollen which contains the male sex cells • filament: supports the anther • pistil: the female part of the flower • stigma: provides a sticky surface to catch pollen • style: supports the stigma • ovary: produces the female sex cells and becomes the fruit www.OneLessThing.net

22. Flower Anatomy www.OneLessThing.net

23. Plant Parts • Flowers: • complete flowers: flowers that have all the parts (sepals, petals, stamen, and pistil) • incomplete flowers: flowers that lack one of the four main parts - petals, sepals, pistil, or stamen • male flowers will not have a pistil and female flowers will lack stamen • monoecious: plants that have male and female flowers on the same plant • dioecious: plants that have male and female flowers on separate plants www.OneLessThing.net

24. Plant Parts • Fruit: • a mature (fertilized) ovary containing the seed or seeds • may be fleshy or dried • fleshy fruit are soft and may be consumed by humans or animals as food which helps to disperse the seeds; examples include pumpkin, apple, tomato • dry fruits have hard seeds www.OneLessThing.net

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