Collenchyma-2 

Celery is the Queen of Collenchyma. 
These bundles stick between your teeth when you munch on Celery. The cell walls have loosely organized cellulose microfibrils and the pectins within are very hydrophilic. This gives flexible, stretchable support to elongating structures like new stems and petioles in the case of celery.

High magnification of Celery Collenchyma. 
Note the uneven wall thickenings. Collenchyma cells contain chloroplasts, however, these probably contribute little to the overall metabolism of the plant. Plastids are NOT well developed in Collenchyma!

This electron micrograph illustrates the uneven wall thickenings as well as the loosely organized cellulose fibrils. The Nucleus is in the center of the cell. Mitochondria are visible in the cytoplasm.

First, find the Epidermis & the Collenchyma can't be far away!

Collenchyma in Ricinis (Castor Bean).
The uneven wall thickenings are on the tangential wall (parallel to the surface). This is called Lamellar Collenchyma. This is not so important but it can be used as a distinguishing trait. In many mature organs it is hard to distinguish lamellar from angular.

Collenchyma in Cannabis sativa. Collenchyma may become Lignified. This occurs in mature stems. How would this affect its mechanical properties?

Collenchyma cells are 
typically Elongate with some overlap at their end walls. The pink color with Toluidine Blue indicates an abundance of Pectins and the absence of Lignin.

Sclerenchyma Fibers have a similar adaptation.