From Cell to Organ-8 
201 Syllabus
From Cell to Organ-8
201 Syllabus
Parenchyma cells can be isodiametric (equal size in all directions) to elongate in shape. They have thin cell walls which contain a lot of hydrophilic pectins which have a characteristic staining reaction.
They usually have well developed Plastids like Chloroplasts or Amyloplasts. Amyloplasts store starch.
 Isodiametric Parenchyma Cell containing Chromoplasts: Each red dot is a Chromoplast that Contains Carotenoids. |
 Elongate Palisade Parenchyma with Chloroplasts |
 Parenchyma from Potato with large Amyloplasts: This is a commercial slide. |
 Parenchyma Cells containing Amyloplasts. This was stained with IKI which has stained the Starch Brown. |
 Some Parenchyma cells are highly branched.  |
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Sclerenchyma
| Sclerenchyma Fibers usually occur in bundles. The individual clells are highly elongated with overlapping endwalls. They are usually lignified. This makes them rigid and strong! |  SEM photo of a Fiber Bundle |
 Individual Fiber from Oak Wood |
 Light Microscope image of a Fiber Bundle. |
Sclerenchyma cells are usually elongate in shape 
and have thick walls impregnated with Lignin. These are called Fibers
& they stain red in most prepared slides
due to their Lignin content.
Lignin makes cell walls extremely strong and inflexible. This makes Sclerenchyma a good support tissue.
Sclerenchyma is usually associated with Vascular Tissues and may completely surround them.
Sclerenchyma Fibers are associated with the Phloem in the image to the right.
