Plant Classification & Identification

1. Plant Classification & Identification Junior High Agriculture

2. Life Cycle • Annual – completes life in one growing season • Stages - germination, growth, flowering, death • Examples – marigolds, corn, soybeans, impatiens, zinnias, wheat

3. Life Cycle • Biennial – completes life in two growing seasons • Stages - germination, growth, dormancy, growth (season 2), flowering, death • Examples – musk thistle, cabbage, primrose

4. Life Cycle • Perennial – will live for more than two growing seasons • Stages - germination, growth, flowering, dormancy, growth, flowering, etc. • May be woody or herbaceous • Examples – Kentucky bluegrass, bur oak, alfalfa, lilac, white clover

5. Growth Habit • Trees – woody perennials with a single, erect trunk • Shrubs – Woody perennials with more than one main trunk • Cacti – Perennials with spines and green fleshy stems

6. Growth Habit • Grasses – plants with jointed, round hollow stems, and parallel veins in leaves • Grass-likes – look similar to grasses without joints, triangular or round stems • Forbs – herbaceous broadleaf plants generally netlike veins in leaves

7. Foliage Retention • Deciduous – lose all leaves in autumn • Evergreen – retain leaves and remain green throughout the year • Drop leaves throughout year, just not all at once • Broad-leaf or Needle-leaf

8. Leaf Characteristics • Five common characteristics of leaves used for identification • Leaf arrangement on the stem • Leaf venation pattern • Complexity of the leaf • Leaf shape • Leaf surface

9. Arrangement on Stem • Alternate – only 1 leaf per node • Opposite – 2 leaves per node • Whorled – 3 or more leaves per node

10. Venation Pattern • Parallel – major veins run the length of the leaf, parallel to the midrib, veins are about equal in size, found in grasses and grass-likes • Pinnate – have one major vein, with secondary veins branching from the midrib, found in trees, shrubs, and forbs • Palmate – have three or more major veins extending from the base of the blade and secondary veins branching from the main veins, found in trees, shrubs, and forbs

11. Venation Pattern Parallel Pinnate Palmate

12. Leaf Complexity • Simple – only 1 blade • Compound – several leaflets attached to a common leaf stalk • Palmately divided – all leaflets branching from 1 point • Pinnately divided – leaflets arranged along both sides of the leaf stalk (Even or Odd) • Twice or Bi-pinnately divided – leaf stalk has 2 or more branches from main stalk

13. Leaf Complexity Even Pinnate Odd Pinnate Twice Pinnate Palmate Simple

14. Leaf Shapes • Cordate – heart-shaped • Deltoid – triangular shaped • Elliptical – broad in middle, tapers at both ends • Lanceolate – narrow with widest point at base • Linear – much longer than wide, sides parallel • Ovate – wide and broad at the base

15. Leaf Shapes Cordate Deltoid Elliptical Lanceolate Linear Ovate

16. Leaf Margins • Crenate – broad, round teeth with narrow, open spaces between them • Dentate – sharp teeth pointing outward • Entire – margin is smooth with no teeth or indentations • Lobed – indentations from ¼ to all of the way to the midrib • Serrate – saw-like teeth that are pointed forward

17. Leaf Margins Crenate Dentate Entire Lobed Serrate

18. Leaf Surface • Glabrous – surface is free of hairs • Glandular – surface has small glands which secrete resin • Hirsute – stiff hairs cover the surface • Pubescent – soft, short hairs cover the leaf surface • Scabrous – surface is rough to the touch, similar to sandpaper

19. Inflorescence Types • The flower inflorescence is the arrangement of the flowers on the stem. A few common types are: • Corymb – short, broad, flat-topped • Head – dense cluster of stalkless flowers • Panicle – flowers developing toward the tips of the branches as the elongate • Raceme – flowers arranged along a main axis on short stems • Spadix – very small flowers massed together, enclosed in a spathe • Spike – flowers along a single axis • Umbel – flat-topped cluster of flower, no central axis

20. Inflorescence Types Corymb Head Panicle Raceme

21. Inflorescence Types Spadix Spike Umbel

22. Tree Fruits • Drupe – fleshy with a single stone or pit (cherry) • Berry – fleshy with several seeds (persimmon) • Pome – fleshy outer coat and stony layer and several seeds within (apple, pear) • Legume – dry, elongated pod that splits in two with several seeds along one edge (honeylocust) • Capsule – dry fruit that splits to reveal many seeds inside (catalpa)

23. Tree Fruits • Achene – small, dry, and hard one seeded fruit, often tightly packed together with hundreds of fruits (sycamore) • Samara – one or two flat wings attached to a seed (maple) • Nut – hard, with an outer husk that does not split open readily and an inner papery to woody shell (black walnut) • Acorn – nut-like fruit of an oak, with a scaly or warty cap

24. Tree Fruits Drupe Berry Pome Legume Capsule

25. Tree Fruits Achene Samara Nut Acorn