1.5

• Ground

  This packing and supportive tissue accounts for much of the bulk of the young plants

  It also functions as food manufacture and storage

  • It contains three main cell types: parenchyma, collenchyma, and sclerenchyma
• Dermal Tissue• This is plant's protective outer covering in contact with the environmentIt facilitates water and ion uptake in roots and regulates gas exchange in leaves and stems
• Vascular Tissue Together the phloem and xylem from a continuous vascular system throughout the plant This tissue conducts water and solutes between organs and also provides mechanical support.
• Nectaries - secret nectars
• Hydatodes - secret pure water.
• Sweat glands - found in dessert plants.
• Osmophores - secrete fragrance in flowers.
• Digestive glands - found in insect eating plants
• Adhesive cells - secrete materials that aid attachment between host and parasite.
• Resin ducts - secrete sticky resin.
• Mucilage cells - found in the growing tip of the roots aid the passage of roots through the soil.tracheids
• Oil chambers - secrete aromatic oils.
• Gum ducts - cell wall modification resulting to production of gums.
• Laticifers - latex secreting glands.
• Myrosin cells - secrete enzymes called myrosinase that produced toxic oil called isothiocyanate.
• 1. Meristematic Tissue - Part of a plant where cell division(mitosis) or production of new cells occurs. a. apical meristem• Tip of stem and roots(shoot or root apical meristem); give rise to the primary meristemb. lateral meristem - Stem and roots• b1. Vascular cambium• b2. Phellogen (cork cambium)c. Intercallary meristem• Internodes and bases of young leaves
• Permanent Tissues - Derived from meristems which have attained maturity form thus perform their specific function.
• epidermis - Outermost layers of cells of the primary plant body Contain stomata, trichomes (appendages)
• • Collenchyma Thickened tissue found in the cortex of the stem and petioles or along the veins of the leaves - Its cells are alive at maturity and have only a primary wall-These cells mature from meristem derivatives that initially resemble parenchyma, but differences quickly become apparentCollenchyr2. Permanent perform
• SCLERENCHYMA - hard and tough cells with a function in mechanical support. Scattered throughout the plant. Found in both primary and secondary tissues.
• TYPES OF SCLERENCHYMA Fibers - known as bast fibers Schleroids or stone cells - similar with fiber thick walls and lignified, may be living or dead at maturity.
• Cork- Outermost tissue; impregnated with suberin (waxy substance)
• Xylem Conduct water and mineral salts upward the plant body
• Phloem Distributes the dissolved food materials between the source and sinks
• Tap root System - Primary root grows vertical downward Branches grows downward or horizontally outwards Functions: Absorb water, mineral, salts from soil, anchorage
• Adventitious Root System - Roots that grow from any part of the plant of the plant body other than radicle
• Fibrous Root System - in monocots (with all adventitious roots)
• Semi roots - Derived from the seeds of grasses.
• Foliar Root System - From leaves mainly petiole or vein (spontaneous or due to injury)
• Stem • Supporting and conducting organ initially developed from the epicotyl• major parts: Bark, Pith and Wood (Composed of xylem made up of vessels, fibers and parenchyma cells)
• Regions of the root

  • root cap - Protects the tender apex

  • region of cell division - 1 to few mm above the root cap; have small cells with thin walls, dense with protoplasm; undergo repeated cell division(meristematic region)
• region of elongation - Lies above meristematic region; extends to 1-5 mm; undergo rapid elongation and enlargement.region of maturation - Lies above meristematic region of elongation, this region produces root hairs
• Erect or strong stems - unbranched; erect; cylindrical; stout; slim jointed stem with solid nodes and hollow internodes
• Weak stems Weak trailing stem- on ground without rooting at the nodes Creeping stem- runner, stolon, offset or sucker Climbing stem- attaches or climbs objects (vines)
• Modified Stem

  • bulb- Short, erect underground stem

  • culm- Flowering stem of grasses and sedges

  • offset- Like runner originates from leaf axil as a short and thickened branch away from the

  mother plant
• rhizome- Horizontal underground stem

  runner - Intermediate aboveground stem with internodes and new plantlet at the tip

  sucker- Shoot arising below the ground from old stem

  tendril- Slender coiling branch for climbing
• • tiller- Shoot produced from the base of the stem or culm• tuber- Thick storage underground stem• corm- Enlarged solid fleshy base
• Stolon - Slender just like the stem of grasses

  CROWN - modified stem with very short internodes.
• Parts of leaf

  Leaf base - part attached to the stem

  Petiole - stalk of leaf

  Leaf blade or lamina - green expanded portion of the leaf
• Dicotyledon - Embryo lies within an axis of two cotyledons