Plant Classification, Function, and Structure

1. Plant Classification, Function, and Structure

2. Introduction • Plants are complex organisms that consist of tissues and cells • Plants consist of leaves, stems, roots, and flowers • Understanding plant growth and the function of plants is very important in horticulture • Horticulturists apply their knowledge of plant anatomy of the different plant organs to promote growth and high quality crops

3. Objectives • Explain why it is important to classify plants • Explain different ways plants are classified according to their taxonomy, and use scientific naming • Explain the hierarchal classification system • Use a dicotymous key to classify organisms • Describe the differences among annuals, biennials, and perennials • Explain the processes of photosynthesis and respiration

4. Objectives (Learning Goals) 4. Identify and describe the functions of the vegetative plant parts a. Leaves Identify and describe the parts the functions of the internal and external leaf structures Discuss the differences between simple and compound leaves, and identify types of compound leaves and their arrangement on a stem b. Stems Identify and describe the parts and functions functions of the internal and external stem structures c. Roots Identify and describe the parts and functions of the internal and external root structures Describe the differences between taproot, fibrous, and adventitious root systems

5. 5. Identify and describe the parts and functions of reproductive plant parts Explain the difference between complete and incomplete flowers Identify types of flower inflorescences 6. Explain the economic importance of all plant parts 7. Describe the structural differences between monocots and dicots

6. Plant Classification

8. Explain why it is important to classify plants • Explain different ways plants are classified • Explain and use Scientific Plant Classification and Naming • Explain the hierarchal classification system • Use a dicotymous key • Describe the differences among annuals, biennials, and perennials

9. Why Classify Organisms? • Classification systems improve: • our ability to explain relationships among things • aid our memory • aid our prediction • provide unique, universally used names for organisms

10. Classifying Plants • Scientists use the similarities of plants to classify them into groups. • There are different classification systems based on • Stem Type • Foliage Retention • Life Cycle • Use • Scientific classification

11. Stem Type Classification • Herbaceous Plants – have stems that are soft and not woody (herbs, vines, turfgrasses) that die back to the ground each year • Woody Plants- shrubs, trees, or certain vines which produce wood and have buds surviving above ground over winter

12. Foliage Retention • Deciduous Plants- leafless during portion of the year (winter) • Evergreen- keep leaves year round • Narrow leaf (needle like leaves) evergreens • Broadleaf (flattened leaf blade) evergreens

13. Life Cycle – • Vegetative phase: part of life when a plant seed germinates and grows producing leaves, stems and roots. • reproductive phase: plant flowers and produces fruit • senescence or dormancy phase: inactive or slow plant growth • Annuals – complete life cycle in less than one year • Biennials – complete their life cycle in two years • Perennials – herbaceous or woody plants that grow indefinitely from year to year

14. Annuals- flowering, then production of seed is a sign of death • Dead-heading: the removal of flowers and seeds to continue life and bloom for longer periods of time • Annuals are often divided into groups based on what season or climate is best for growth

15. Biennials • During first season of growth the plants grow vegetatively then become dormant in winter • The following spring the plants produce flowers and fruit then die.

16. Perennials: plants that live for more than two seasons • Above ground portions of perennials generally die in winter but grow new shoots and leaves the following spring from the below-ground portions of the plant • Can be deciduous or evergreen

18. Hardiness • Tender plant: unable to survive extreme climate and temperature • Hardy plant: able to withstand colder temperatures

19. Use • Edible • Ornamental • Medicinal • Back in the day: • Poisonous • safe

20. Scientific Classification

21. Scientific Naming • Avoid confusion concerning the names of plants. • Scientific names of plants are expressed in Latin because it is a international language and was used by early scholars to express plant names

22. Scientific Classification • Based on morphology of plants (form and structure) • Botanical Nomenclature: scientific classification of plants • Includes Genus, Species, Variety, Cultivar • Scientific Name: • written in Latin • First letter is always capitalized and the species is lower case • Plants in same genus have similar characteristics • Variety or cultivar: given to plants of the same species that have a sufficiently different appearance

23. Latin names of plants are italicized: • Because it is conventional to italicize words and phrases that are expressed in a different language. • Example - The most commonly known cultivars of Acer rubrum ( red maple) are “Red Sunset” and “Autumn Flame,” which are the most reliable for brilliant reds and a long-lasting display of foliage.

24. The generic name of the plant is: • Placed first and begins with a large letter. • Examples: Acer-(maple), Papaver-(poppy), Pinus-(pine)

25. When classifying plants, it is important to first understand that the more they are categorized the more specific the plant categories are. Classification begins with Kingdom and continues with Phylum, Classes, Orders, Families, Genera, and Species. Each of these can be further subdivided.

27. A genus can be defined as: • A group of plants that have more in common with each other than they have with the members of any other genus.

28. A species can be defined as: • A group of plants that are alike in almost every feature and consistently produce like plants. • Example - Betus lutea is yellow birch (lutea means “yellow”)

29. TAXONOMIST • A person who identifies and classifies plants!

30. Kingdom Plantae • Plants dominate the land and many bodies of water. Plants exhibit tremendous diversity. Some plants are less than .04 inches in width, and some plants grow to more than 328 ft in height. • All organisms in this kingdom are multicellular and most are photosynthetic and live on land.

31. The first true plant is thought to have been similar to a green alga, with adaptations that enabled it to survive the dry conditions of land. • From that algal ancestor, a wide variety of plants have evolved.

32. Phylum Bryophyta • Know as mosses: • More than 10,000 species • No vascular tissue • Seedless, reproduce with spores • Sphagnum moss is a genus of moss that is a major component of peat bogs and has a high water holding ability, making very useful to the world of horticulture

33. Phylum Hepatophyta • Know as liverworts • 6,500 species • Unusual looking plants that grow in moist shady areas • Non-vascular

34. Phylum Anthoceroophyta • Known as Hornwarts • 100 species • Nonvascular • Resemble liverwarts • They share an unusual characteristic with algae; each cell usually has a single large chloroplast rather than numerous small ones

35. Phylum Psilotophyta • Known as whisk ferns • 10-13 species • Vascular, seedless • Not actually ferns, have no leaves or roots • Epiphytes- grow on other plants but not considered parasites

36. Phylum Lycophyta • Club Mosses • 1,000 species • Vascular seedless • Look like miniature pine trees • Bear spores and have roots • Many are endangered species

37. Phylum Sphenophyta • Horsetails • 15 species • Vascular seedless • Jointed stems • Outer cells contain silica, the major component of sand • Often used by american pioneers to scour pots and pans

38. Phylum Pterophyta • Ferns • 12,000 species • Vascular, seedless • Beautiful and feathery leaves • Most have an underground stem • Most produce spores on the underside of their leaves

39. Phylum Cycadophyta • Cycads • Gymnosperms • Vascular with seeds • 100 species • Most lived in age of dinosaurs • Now mostly ornamental • Look fernlike

40. Phylum Ginkgophyta • Ginkgo • Gymnosperms • Vascular with seeds • 1 species • Also flourished in age of dinosaurs • Ginkgo biloba is only remaining species native to China

42. Phylum Coniferophyta • Conifers • 550 species • Gymnosperms • Vascular with seeds • Important sources of wood, paper, turpentine, resin, ornamental plants (used in horticulture) • Gin flavored with juniper seeds

44. Phylum Gnetophyta • Gnenophytes • Gymnosperms • Vascular with seeds • 70 species • Odd cone bearing plants • Ephedra is a species that produces the drug ephedrine used for weight loss

45. Phylum Anthophyta • Flowering Plants • Vascular with seeds • Produce flowers for reproduction • 240,000 species, largest phylum • Monocots vs. Dicots

47. Parts of the Plant and Their Functions Chapter 4

48. Introduction • Plants are living organisms that have complex chemical processes that direct growth and development • They have four main body parts where these processes take place. • Leaves • Stems • Roots • Flowers

49. Plant Parts FLO WERS Leaves LEAVES STEMS ROOTS ROOTS

50. Plant Parts • Vegetative • Leaves, stems, roots • Reproductive • Flowers