* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download What does a stem do? Parts of the stem
Survey
Document related concepts
Magnesium in biology wikipedia , lookup
Plant ecology wikipedia , lookup
Venus flytrap wikipedia , lookup
Plant stress measurement wikipedia , lookup
Ornamental bulbous plant wikipedia , lookup
Plant physiology wikipedia , lookup
Photosynthesis wikipedia , lookup
Plant reproduction wikipedia , lookup
Plant morphology wikipedia , lookup
Plant nutrition wikipedia , lookup
Evolutionary history of plants wikipedia , lookup
Sustainable landscaping wikipedia , lookup
Plant evolutionary developmental biology wikipedia , lookup
Flowering plant wikipedia , lookup
Transcript
Botany for Master Gardeners Part II What you should know by the end of today’s session Selected plant parts and their How to tell a stem from a root “reasons for being” How to recognize a simple and compound leaf How to describe how water gets to the top of trees How to tell a monocot from a dicot What does a stem do? Physically support leaves, flowers & fruits Transport water, minerals & nutrients Parts of the stem node = place where leaf is (or was) attached to the stem internode = distance between nodes Provides storage in some plants Note: Stem parts are important in plant identification! terminal bud One year of growth from one bud scar to another A closer look at buds bud scales axillary or lateral bud leaf scar bud scale scar node http://www2.una.edu/pdavis/images/trees/twigs/fraspcm.jpg 1 lateral bud Let’s review bud scale scars leaf scar Lateral or axillary buds Located in the angle where the leaf attaches to the stem Axillary bud may produce lateral shoot or branch Terminal bud What’s inside the stem? apical meristem vascular bundles leaf primordia axillary buds internode node corn cortex cells add structural strength to the stem 2 phloem phloem on the outside vascular bundle xylem on the inside Notice the positions of the tissues as related to the outer layer of the stem! Stem cross-section Herbaceous monocot (corn) What does the phloem do? transports nutrients in sap What does the xylem do? xylem transports water and minerals Cross-section of stems Herbaceous monocot (corn) Herbaceous dicot (clover) Herbaceous dicot (clover) phloem Note: A vascular cambium is between the xylem and phloem in dicots, but not in monocots xylem Notice the relative position of the xylem and phloem! Stem cross-sections Herbaceous monocot (corn) What else to you notice? A dicot stem has vascular bundles in a ring vascular cambium Woody dicot (maple tree) 3 vascular cambium vascular cambium bark phloem xylem bark phloem xylem What’s this area? www.unlv.edu/.../ Secondary/Secondary.html Vascular cambium o Cambium is a meristematic tissue, meaning it divides to produce new tissues o Cambium divides to produce o xylem: to the inside (heartwood, pith) o phloem: to the outside (part of bark) o Responsible for “girth growth,” or increased stem diameter in woody plants Xylem cells o Carry H2O & dissolved nutrients o Cells are: o long, open-ended, connected end to end o have thick cell walls o resemble straws ? What is bark? Answer. Bark is the outer layer of cells on a tree containing cambium, compressed phloem, and cork ? What direction does the xylem transport its materials? Answer: xylem cells transport water and minerals primarily from the soil upwards 4 ? Phloem cells What direction does the phloem transport its materials? o Transport actively photosynthetic products o from leaves to roots, stems, flowers & fruits o Cells are: o long and tube-like o without extra cell wall thickening Answer: Phloem cells transports nutrients downward, sideways, and even “up” wherever the plants needs the energy Let’s review vascular bundles Phloem transports photosynthetic products to areas of the plants needing energy Vascular bundle Xylem is like tiny straws and transports water and minerals from the soil to other parts of the plant What do roots do? o take up water and minerals o anchor the plant o store food reserves in over-wintering perennials Kinds of root systems o tap root, can be large of narrow o fibrous or lateral roots form a network in the ground 5 What’s inside a root? ? How does this differ from a stem? Answer: The vascular system is in the center buttercup What’s inside a root? cortex xylem phloem cambium in woody roots buttercup Unique to roots! Origin of lateral roots root cap located at root tip & protects growing point root cap Notice the root cap on the lateral root Root hairs, another unique feature ? What is the function of root hairs? Answer: Absorb water and minerals from the soil Root hairs on a radish seedling Root hairs • delicate • thin-walled • room for lots of water • has lower water pressure than the outside soil http://iweb.tntech.edu/m caprio/Root_hair_BW.J PG 6 What do leaves do? Major leaf parts • lamina (leaf blade) highly variable in size and shape o photosynthesize o respire o transpire • petiole - stalk at base of leaf that attaches leaf blade to stem Leaf vein patterns Remember monocots & dicots? leaf blade petiole http://www.csdl.tamu.edu/FLORA/201Manhart/veg/leaf.venation/image1.gif dicots monocot Let’s practice Monocot or Dicot? ? 7 ? ? Compound vs. Simple leaves ? ? Simple leaf Buds are in the axils between leaf and stem Hint: Where is lateral bud? 8 Compound leaves Simple or compound? leaflet pinnately compound palmately compound Where is the bud? leaflet pinnately compound ? simple ? ? pinnately compound ? leaflet palmately compound 9 Albizzia – bipinnately compound What is photosynthesis? Answer. Photosynthesis is the process whereby plant use the energy of light to convert carbon dioxide and water to sugars http://www.eeb.uconn.edu/Courses/EEB271/Fabales/Albizzia%20leaves.jpg ? Sugars produced through photosynthesis are the building blocks of life as we know it What is respiration? In Out carbon dioxide, sugars water water oxygen Answer. Respiration is the opposite of photosynthesis In respiration, sugars, water, and oxygen are used and carbon dioxide and water are released The photosynthesis factory Epidermis True or False ? Only plants photosynthesize and only animals respire Answer: Only plants What is the leaf epidermis? Answer: The epidermis is the top and bottom layer of cells on a leaf photosynthesize but both plants & animals respire 10 Leaf model What do stomates do? mesophyll open closed Stomates are small pores on the leaf epidermis used for gas exchange What is transpiration? Answer: Transpiration is water loss (as vapor) from a plant Transpiration rate is controlled by opening and closing of the stomates, which is influenced by humidity, temperature, and light The Elements . . . Finally! Putting it all together ? How does water get from the soil to the top of a tree? Let’s review Root hairs (often with the help of mycorhizzae) absorb water from the soil Name three critical processes carried out by leaves Xylem cells transport water via capillary action and cohesive force of water Answer: photosynthesis, respiration, and transpiration Stomates control evaporation which creates a lower pressure in the vascular system What role does transpiration play in water movement in plants? Answer: transpiration creates a lower pressure in the vascular system which draws water from the soil 11 What do flowers do? o reproduce – It’s all about sex o if fertilization occurs, seeds are produced and carried in cones (conifers) or fruits (flowering plants) flower It is not always what it seems! Parts of a flower filament anther style stigma Lily Flower parts anther stigma sepal 12 Flower Types • Complete – Has all floral parts present (sepals, petals, stamens, pistils) • Incomplete -flower lacks 1 or more of the 4 parts Complete or Incomplete? begonia “male” flower “female” flower (staminate) (pistillate) Kinds of plants with catkins are usually imperfect. Can you think of more examples? poplar Flower Types, Continued • Perfect – Has both stamens and pistils (male and female parts) • Imperfect – Lacks either stamens or pistils New Question. Perfect or Imperfect? begonia Answer: These are imperfect flowers. Perfect flowers have both male and female parts in the same flower Remember, It’s All About Sex! alder 13 pollen on sticky surface of stigma pollen grains Fertilization pollen tube ovule ovary Ovary cross-section of ovary Guess the pollinator The old birds and bees thing big leaf maple willow beetles wind cape fuchsia hummingbirds Guess the pollinator yarrow skunk cabbage butterflies flies cat’s ear bees 14 One More Thing to Learn Question: What is the floral difference between monocots and dicots? Answer: Monocots have flower parts in multiples of 3; Dicots are in multiples of 2, 4 or 5 Summary of differences, monocots & dicots Time to practice with pictures! ? ? 15 ? ? ? ? Fun Activity ? 16 Resources Capon B, 1990. Botany for gardeners, Timber Press, Portland OR, 220 pp. ISBN 088192-258-7 (paper). Resources Baumgardt, John Philip. 1992. How to identify flowering plant families: a practical guide for horticulturists and plant lovers. Timber Press, Portland, OR, 269 pp. ISBN 0-917304-21-7. Resources Elpel, Thomas. 1967. Thomas J Elpel’s herbal field guide to plant families, 4th ed., HOPS Press, Pony, MT, 196 pp. ISBN 1-89278407-6. Acknowledgements Web Sources U WI – Stevens Pt U CT UC Davis U Florida U Chicago U Texas WSU CO St U Purdue U UC Berkeley Ohio St U OSU CA St U Stanislaus U NE Lincoln UCLA Botanical Soc America U NM Rutgers U Southern IL U U System GA Princeton U U KY U North AL Texas A&M U U WI – Madison Sidwell Friends School U HI IA St U Stanford U Queens U Charlotte Eastern OR U – La Grande Texas Tech U U IL Urbana-Charlotte U of MD U AZ Vanderbilt U U Miami MI St U Many photographs by Linda R McMahan, OSU Extension, Yamhill County Cleveland St U Grand Rapids Comm C Wilkes U Cornell U Stony Brook U Maricopa Comm C Some slides from an original presentation prepared by Ann Marie VanderZanden 17