Скачать или смотреть 🍂 Leaf Venation

🍂 Leaf Venation is arrangement of veins in a leaf's lamina. It's a characteristic feature of leaves that helps identify plants.
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○ ¹ Reticulate Venation - A network of veinlets, common in Dicotyledonous plants 🥑Magnoliid leaves typically have netted or branching veins
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○ ² Parallel Venation - Veins run parallel to each other, common in monocotyledonous plants 🌾
○³ Pinnate Venation - A midvein or midrib with secondary veins branching out to either side
○⁴ Palmate Venation - Several main veins radiate from a single point at base of leaf
💮 Basal Angiosperms do not fit well into either category, although they were once grouped with dicots due to their leaf veination & two seedling leaves (cotyledons).
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★ Functions

● Mechanical stability - Venation geometry & density affects a leaf's mechanical stability
● Transport of water & carbohydrates - Transport properties of water & carbohydrates are influenced by venation architecture
● Rigidity Veins provide rigidity to leaf lamina
Examples of plants with different venation Avocado has pinnate venation, Grasses have parallel venation, & Kukui leaf (Aleurites moluccana) has palmate venation.
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○ Vein - A vascular bundle made up of xylem & phloem cells
○ Xylem - Cells that bring water & minerals from roots into leaf
○ Phloem - Cells that move sap out of leaf
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◆ pedate - Palmate, with cleft lobes
◆ reniform - Shaped like a kidney, with an inward curve on one side
◆ rhomboid - Diamond-shaped
◆ sagittate - Arrowhead-shaped with lower lobes folded or curled downward
◆ spatulate - Spoon-shaped; having a broad flat end which tapers to base
◆ trullate - Shaped like a masonry trowel
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Tip
◆ retuse - With a shallow notch in a round apex
◆ subulate - Awl-shaped with a tapering point
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Tip/ Base
◆ rounded, rotundifolius - Circular, no distinct point
◆ subobtuse - Somewhat blunted; neither blunt nor sharp
◆ truncate - With a squared-off end
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● undulate - Wave-like
● unifoliate - compound leaves - With a single leaflet; it is distinct from a simple leaf by the presence of two abscission layers and often by petiolules & stipels.
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