Basic ClassificationsVascular vs. Non-vascularSeed vs. SeedlessFlowering vs. FlowerlessBig 2 Vascular Plant Divisions Flowering Plants (Anthophyta) Cone Bearing Plants (Coniferophyta)
Plant Life CyclesAnnuals - complete life cycle (seed to seed) in one yearBiennials - require all or part of 2 years to complete life cyclePerennials - live longer than 2 years Herbaceous - soft stems that die back in winter Woody - trees, shrubs, etc.
Monocots vs Dicots Structure Monocots Dicots Seed Leaves One TwoVascular System Xylem & phloem Xylem & phloem in in bundles, dispersed rings; xylem inner ring, in stem phloem outer ring Floral Parts Usually threes or Usually in multiples multiples of three of four or five Leaves Often parallel-veined Generally net-veined
Woody Stem AnatomyAdapted from Panshin & DeZeeuw, 1980,Textbook of Wood Technology, 4th edition, p17.
Stem TissuesXylem - conduct water & mineralsPhloem - carry sugars & starchesEpidermis - Outermost layer of plant tissue, protective layerCortex - primary tissue surrounding vascular bundlesPith - thin-walled cells at center of stem
Specialized Above-Ground StemsCrowns - compressed stems with leaves and flowers on short internodesSpurs - short side stems arising from main stem, often bear fruit on treesStolons - fleshy or semiwoody, elongated, horizontal stems, often at soil surface
Specialized Underground StemsTuber - enlarged, short, fleshy underground stem tipRhizome - horizontal underground stem, may be compressed and fleshy or slender with elongated internodesBulb - short, compressed, underground stem with central bud at tip of stem, surrounded by fleshy scales (leaves)
Specialized Underground StemsCorm - solid, swollen underground stem with dry, scale-like leavesTuberous stem - short, flat, enlarged underground stem with buds and shoots at top and fibrous roots at bottom
Types of LeavesScale leaves (cataphylls) - enclose and protect rhizomes and budsSeed leaves (cotyledons) - store food for seedlingsSpines & Tendrils - protect or help supportStorage leaves - found on bulbous plants & succulents, store foodBracts - modified, often brightly-colored leaves around flowers
Species with Imperfect FlowersMonoecious both pistillate and staminate flowers occur on same plant • birch, pecan, squashDioecious pistillate are on one plant, staminate on a different plant • ginkgo, holly, pistachio, kiwi
PollinationExchange of pollenNumerous mechanisms insects, birds, bats, wind, rainFlowers are optimized for their pollination vector
Seed AnatomyEmbryo - miniature plant in an arrested state of developmentEndosperm - food supply (can be comprised of proteins, carbohydrates, fats)Seed coat - hard outer covering that protects from disease and insects; also repels water
GerminationActivation of embryo within seedPreceded by water penetrating seed coatOxygen, favorable temperature, and (in some species) light required