Horticulture Class -- Chapter 3 Notes

Week 3

Parts of Plants

  • Leaves
  • Stems
  • Roots
  • Flowers

Leaves – are the food factory of the plant.

  • Leaf margins :

  • Leaf arrangements –

External leaf structure

  • Petiole – leaf stalk
  • Blade – large, flat portion, has veins, midrib
  • Forms – physical appearance of leaf with differing margins (edges of plant leaves).

Internal Leaf structure

  • Epidermis –skin of leaf – prevents loss of too much water.
  • Guard cells –open and close stoma (small cells on bottom of leaves that give off moisture and oxygen).
  • Transpiration – the process of plants giving off water, CO2 and O2 exchange.
  • Chloroplasts –cells that contain chlorophyll and give plants green color.
  • Photosynthesis – plants making food.

Internal Leaf Structure:

  • Cuticle: Waxy layer water proofing upper leaves.
  • Xylem: Living vascular system carrying water & minerals throughout plant.
  • Phloem: Living vascular system carrying dissolved sugars and organic compounds throughout plant.
  • Stomata: Opening between guard cells for gas & water exchange.

Respiration

Happens all the time.

Produce more oxygen through photosynthesis than is used in respiration by roots, stems, and leaves.

Stems

  • Move materials from roots to leaves and from leaves to roots
  • Support leaves and flowers
  • Food storage.

External stem structure

  • Lenticels – outside of stem – breathing pores.
  • Bud scale scars –they indicate where a terminal bud had been. Distance from one to another indicates 1 years growth.
  • Leaf scar – where leaves had been attached.

Internal stem structure

  • Xylem – water and minerals travel up
  • Phloem – manufactured foods travel down
  • Dicots – plants with 2 seed leaves
  • Cambium –separates the layers of xylem and phloem in dicots from each other. Phloem outside, xylem on inside.
  • Tree bark is inactive/old phloem cells, heartwood is old xylem cells.
  • Monocots – one seed leaf.

Roots

  • Anchor plant
  • Absorb water and minerals
  • Store plant food
  • Propagate plants

Root structure

  • Tap root vs. fibrous root (easier to transplant)
  • Root hairs – absorb water and minerals
  • Root rot – no oxygen exchange happens due to saturation around roots.

Flowers, fruits, and seeds

  • Pollination – done by insects, wind
  • Parts of flower –
  • Complete flower –both male and female parts
  • Male part is called stamen (anther and filament)
  • Female part is called pistil (stigma, style, ovary)
  • Sepals – green leaves that cover bud and form calyx.
  • Petals – colored leaves that attract insects
  • Incomplete flower – missing either the pistil or stamen.
  • Pistillate flower – has pistil, sepals, and petals.
  • Staminate flower – has stamen, sepals, and petals.

States and their main Horticultural crops:

  1. Washington –
  2. California –
  3. Vermont –
  4. Kentucky –
  5. Florida –
  6. Texas –
  7. Indiana –
  8. Michigan –
  9. Hawaii –
  10. Georgia –

Parts of the plant cell:

Week 4 notespage 1