Leaf Blade: Wide flattened area of leaf for concentrating sunlight on photosynthetic cells.
Petiole: Short stem that attaches leaf to main stem or branch.
Veins: Vascular bundles within leaf for transport.
Node: Growth region of stem where leaves or new branches arise.
Auxiliary bud: Baby leaf or stem (next year’s growth).
Leaves are also commonly adapted for other functions such as food and water storage, support and defense.
A bulb onion has a very short stem with thick fleshy scale leaves
Cacti have evolved their leaves in to woody non-photosynthesis spines. The small surface area of the spine reduces water loss and protects the plant. Because of their lack of large leaves, cacti have most of their photosynthesis in their stems.
Some plants have evolved their leaves in to the role of petals to help in attracting pollinators.
Carnivorous plants have evolved their leaves in to a form of insect trap. The most common being the Venus Fly Trap.