Introduction to Botany

Transcription

1 Introduction to Botany Jan Zientek Senior Program Coordinator Cooperative Extension of Essex County 1

2 Poor Man s Umbrella Gunnera insignis 2

3 Basic Botany The study of the growth, structure and function of plants BOTANY Evolution Taxonomy Plant morphology Plant physiology and cell biology Plant reproduction Plant hormones and growth regulators Plant Functions 3

4 PLANTAE Eukaryotic (with a nucleus) Cell walls with cellulose Food stored as carbohydrate Multi-cellular autotrophs Chloroplasts (green) Non-motile Several phlyum Development of pollen DOMAIN KINGDOM PHYLUM CLASS ORDER FAMILY Genus species 4

5 Common Name vs Scientific Name Foxglove Digitalis purpurea Maybe local name General Universally recognized Specific Common Name vs Scientific Name Fire bush Scarlet bush Texas firecracker Corail (or is it Koray?) Polly red head Hamelia patens Hummingbird bush Ix-canan 5

6 Plant phylums (types) Mosses Liverworts Hornworts Club mosses Horsetails Ferns Cycads Ginkgoes* Gnetophytes Conifers Until sometime in the 90 s Ginkgoes were thought to be related to conifers. Why? Because botantists (taxonimists) were ready for a phylum with one member! Plant Types Mosses are non-vascular plants -- they cannot transport fluids through their bodies. Instead, they must rely on surrounding moisture to do this job for them. Ferns and allies have a vascular system to transport fluids through their bodies but like the mosses, they reproduce from spores rather than seeds. The main phylum, theferns (Filicinophyta = Pteridop hyta) includes around 12,000 species. 6

7 Monocots: have a single cotyledon (seed leaf), flower parts in multiples of three, parallel venation of leaves, scattered vascular bundles in stems. Around 30,000 plants are classified as monocots including many of the prettiest members of kingdomplantae: orchids, lilies, irises, palms and even the Bird-of- Paradise plant. The grasses which carpet our lawns and meadows are also monocots. Dicots: The vast majority of plants are Dicots. Most trees, shrubs, vines, and flowers belong to this group of around 200,000 species. Most fruits, vegetables and legumes come from this class. They have two cotyledons, flower parts in multiples of 4 or 5, netted veins, and stems which are organized in a ring pattern. 7

8 Plants can be classified by the type of their seed structure Gymnosperm: naked seed Angiosperm: seed within a fruiting body The gymnosperms add the next level of complexity to plant evolution: they reproduce from seeds instead of spores. The seeds, however, are "naked" - not covered by an ovary. Usually, the seed is produced inside a cone-like structure such as a pine cone hence the name "conifer." Some conifers, such as the Yew and Fir, produce their seeds inside a berry-like structure. Ginkgo Conifers are fairly easy to identify: In addition to the aforementioned cones, these trees and shrubs typically have needle-like, scale-like or awl-like leaves. And they never have flowers. 8

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10 Lifecycles help gardeners distinguish between plants: Annuals Biennials Perennials Annuals complete life cycles in one season 10

11 Biennials live for 2 years, flower, then die Perennials live for 3 or more years, flower each year and usually do not die after flowering. Structures of Plants Roots Stems Leaves Flowers Seeds 11

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13 Root cross-section 13

14 Examples of Stem Structure Herbaceous monocot and dicot stem 14

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16 Leaves Are the center of food production in the plant Photosynthesis and respiration occur there Leaves are either simple (one blade) or compound (multiple blades) 16

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18 Stomata 18

19 Are sexual organs Inflorescence Perfect flower Imperfect flower Monoecious Dioecious Flowers The Flower 19

20 Seeds Allows for survival of a species into the next growing season Adapted to recognize ideal growing conditions Source of energy for young, emerging plant 20

21 Apical meristem: point of vigorous cell division and growth 21

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25 Photosynthesis Is the chemical process that creates complex sugars from water, carbon dioxide and sunlight. Photosynthesis occurs in the chloroplast Chlorophyll is the green pigment that allows photosynthesis to occur. 25

26 RESPIRATION The transformation of stored chemical energy to usable energy for growth and development C 6 H 12 O 6 plus O2 6CO 2 + 6H 2 O + energy TRANSPIRATION The uptake and release of liquids and gases, especially water and CO 2, by plants. Important in the regulation of water within the plant (wilt, turgor, stomatal activity, etc.) 26

27 Hormones Chemical substances that control patterns of growth and development, and responses to environmental conditions Influencing Plant Growth Auxin phototropism, gravitropism, apical dominance Gibberellins increased plant and fruit size Cytokinins cell division, sprouting Dormin accelerates abscission, promotes dormancy Ethylene fruit ripening, senescence Gardeners use hormones to induce flowering, fruiting, root cuttings, induce or break dormancy, ripen fruit or seeds, chemically prune plants, and control growth. 27

28 Physiology-Phototropic-Response References Biology, by Miller and Levine, Prentice Hall, Upper Saddle River, NJ, 2002 Botany: A Golden Guide, by Alexander, Burnett and Zim, Golden Press, NY, 1970 Botany for Gardeners, by Capon, Timber Press, Portland, OR, 2005 Horticultural Science, by Jannick, Freeman and Co., San Francisco, CA, 1972 Plant Physiology, by Bidwell, MacMillan Publishing Co., NY,