StemsII Primary thickening meristem occurs in many monocots
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Stems-II
Primary thickening meristem occurs in many monocots
Primary thickening meristems
Primary Thickening Meristem
Banana “tree”
Foxglove vascular ring
Eustele in dicots
Alfalfa and ragweed VB
Clover fasicular cambium spreads to interfasicular region
Secondary growth restricted to VB
Ordinary secondary growth in dicots and gymnosperms secondary xylem and phloem develops from the vascular cambium
Anomalous Secondary Growth • Localized cambial activity because some regions of cambium die • Uneven amounts of xylem and phloem • Multiple cambia develop • Concentric (or successive) layers of vascular cambium • Monocots
Monocots Yucca brevifolia Cocus nutifera
Cordyline (Ti plant)
Secondary Growth in Monocots • Meristem (cambium) becomes distinct outside the outmost VB in the stem • Secondary Thickening Meristem produces – Cells outward that differentiate into parenchyma becoming part of a secondary cortex – Cells produced inward are either • Conjunctive parenchyma that become sclerified • Parenchyma that differentiates into fibrovascular bundles (called secondary bundles)
Secondary thickening meristem in Cordyline (Ti plant)
Palm trunk Royal palm
Palm trunk
Stems (gymnosperms, dicots, and monocots) also contain a variety secretory structures Ducts may contain resins, gums, mucilage produced by parenchyma (epithelial) cells lining the duct Resin ducts in Pinus and in Artemesia
Resin duct in poison ivy stem
Oil and mucilage cells
Laticifers • Secretory structures (of one or more cells) that produce latex (latex is a milky secretion produced by many plants with varied composition – Non-articulated laticifers consist of extremely elongated single cells (cell growth keeps pace with the growth of the stem) – Articulated laticifers are composed of many individual cells that are usually interconnected by holes in their common walls (like vessels)
Non-articulated laticifer in Euphorbia
Articulated laticifers
- Primary thickening meristem in monocots
- 3 tissues of a plant
- Difference between monocot and dicot
- Root hair structure
- Monocots and eudicots
- Monocots and eudicots
- Monocot orders
- Comparing monocots and dicots
- Www.youtube.com
- Monocots vs dicots
- Monocots vs dicots
- Plant reproduction
- Nourishing element
- Classification of thickening agents
- Mother sauces and derivatives
- Shear thinning vs shear thickening
- Emulsifier recipes
- Thinning and thickening in image processing example
- Mother sauces derivatives
- Ligamentum flavum thickening
- Peribronchial cuffing
- Ligamentum flavum thickening
- Thickening of uterine lining
- Morphological dilation
- Erosion image processing