Flowering plants - Leaves
Shoot = stem and leaves
D - blade
E - petiole
D + E - a simple dicot leaf (axillary bud is not visible)
A and C are nodes (place on stem where leaf & bud are attached)
B - internode (stem between nodes)
F - the growing point of the stem, location of a terminal bud (if dormant) or immature shoot (if growing) with apical meristem at tip.
Leaf surface, showing ordinary epidermal cells and a stoma.

A - stoma (two guard cells and the pore between them; the pore is only present when the stoma is open)
B - the pore of the stoma (opening between guard cells)
C - one of the two guard cells
Leaf cross section (high power):

A - palisade parenchyma (= palisade mesophyll)
B - spongy parenchyma (= spongy mesophyll)
C - stoma, showing the two guard cells in cross sectional view

Note the chloroplasts (small, pinkish structures) and nucleus (larger, darker pink spot) in each cell of leaf parenchyma.

Note the greater amount of air space between cells in spongy parenchyma.
Another leaf cross section, at lower power, showing the midrib (the large vascular bundle, or vein, in the middle of most leaves)

A - xylem tissue
B - phloem tissue
C - upper epidermis
D - lower epidermis
All photos by Robert Bowker
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