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Ragweed pith
Primary pit fields
Primary pit fields
Wall, face view
Nucleate cells
Compact parenchyma
Sclerenchyma
Intercellular spaces
Leaf, xs
Chlorenchyma
Shoot tip, ls
Apical meristem
Vascular cambium
Secretory duct
Resin canal
Clusia duct
Root cortex
Leaf aerenchyma
Air chambers
Air chambers
Aerenchyma, Acorus
Stellate cells
Epidermis
Endodermis
Phloem, ls
Phloem, xs
Transfer cells
Bean cotyledon
Acorn, starch
Potato starch
Ice plant cell
Tannin cell
Small cells

Fig. 3.6-3a and b. Transverse section through a tuber of potato (Solanum tuberosum). Potatoes are well-known for being starchy, and a potato tuber comes close to being 100% starch storage parenchyma. The potato “skin” is a parenchymatous bark and there are a very few tiny vascular bundles (one is present in the high magnification view). You can see the parenchyma cells have very thin walls and many red-stained starch grains. This actually appears to be too few starch grains – perhaps this sample was taken from a young, growing potato that had not yet completely filled itself, or maybe it was taken from an old potato that had been stored so long it had already used much of its starch just for its own survival.