Thickened cornerThe wall is thickest at the corners. Extra wall material is laid down where cells meet, and that gives the tissue its strength.
Primary cell wallA primary wall of cellulose and pectin. It has no lignin, so it can stretch while the stem is still growing.
Living contentsCollenchyma cells stay alive when mature. The protoplast, the living part of the cell, fills the space inside the wall.
Parenchyma 4
Thin cell wallA thin primary wall of cellulose. Thin walls are the mark of parenchyma.
Intercellular spaceAn air-filled gap between cells. These spaces let gases move through the tissue.
VacuoleOne large central vacuole. It stores water, ions and other dissolved substances.
ChloroplastChloroplasts carry out photosynthesis. Parenchyma cells that hold them are called chlorenchyma.
Sclerenchyma 5
Lignified wallA thick secondary wall hardened with lignin. It makes the tissue hard and stiff.
Cell cavityThe empty space left inside. A mature sclerenchyma cell has lost its living contents.
PitA thin place left as the wall thickened. Pits of neighboring cells meet in the shared wall.
Stone cellA short, stocky sclerenchyma cell, also called a sclereid. Groups of stone cells give a pear its gritty feel.
FiberA long, slender sclerenchyma cell with pointed ends. Fibers of flax and hemp are made into rope and cloth.
How this list was compiled: Every name was checked on 2026-10-01 in at least two places, for facts only and with nothing copied. (1) W. C. Stevens, Plant Anatomy (1907), the chapters on the primary tissues and on the stone cells, https://archive.org/details/plantanatomyfro00stev (public domain). (2) University of Vigo, Atlas of Plant and Animal Histology: Parenchyma, and Support (collenchyma and sclerenchyma), https://mmegias.webs.uvigo.es/02-english/1-vegetal/guiada_v_parenquima.php and https://mmegias.webs.uvigo.es/02-english/1-vegetal/guiada_v_sosten.php. (3) Wikipedia, text only: Ground tissue, https://en.wikipedia.org/wiki/Ground_tissue. (4) J. N. Martin, Botany for Agricultural Students (1919), the section on strengthening tissues, https://archive.org/details/botanyforagricul00mart (public domain). (5) A. J. Eames and L. H. MacDaniels, An Introduction to Plant Anatomy (1925), the chapters on the cell and on fibers, https://archive.org/details/in.ernet.dli.2015.270773 (public domain). (6) T. F. Hanausek, The Microscopy of Technical Products, translated by A. L. Winton (1907), the sections on bast fibers and stone cells, https://archive.org/details/microscopytechn00wintgoog (public domain). Licence: own work
The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work
How it works
This collenchyma cells diagram shows the tissue cut across, with its walls thickened at the corners. Two more views show parenchyma and sclerenchyma the same way. Tap a name to read about the part, or press Quiz me.
Read the full guide
Tell the three tissues apart by the wall
Collenchyma cells are alive, and their primary wall is thin along the sides and thick at the corners. Parenchyma cells are alive too, with thin walls all round and small air spaces between them. Sclerenchyma cells have a thick lignified wall with pits, and only a small empty cavity is left inside.
The second view is also a chlorenchyma cell diagram
Parenchyma cells that hold chloroplasts are called chlorenchyma. In the third view, the long cell is a fiber and the short, stocky one is a stone cell.
Lumen is accepted for cell cavity, sclereid for stone cell and protoplast for living contents.
Questions and answers
What is the difference between parenchyma, collenchyma and sclerenchyma?
The cell wall. Parenchyma cells have thin walls. Collenchyma cells have a wall thickened in places, most often at the corners. Sclerenchyma cells have thick, lignified walls and are dead when mature.
Are collenchyma cells living or dead?
Living. A collenchyma cell keeps its contents, and its wall is a primary wall of cellulose and pectin with no lignin, so the tissue can stretch as a young stem grows.
Where is collenchyma found in a plant?
Just under the epidermis of young stems and leaf stalks, as a ring or as separate strands. It supports parts of the plant that are still growing.
What is chlorenchyma?
Parenchyma whose cells contain chloroplasts and carry out photosynthesis. The mesophyll inside a leaf is chlorenchyma.
Why do pears feel gritty?
Small groups of stone cells are scattered through the flesh of a pear. A stone cell is a short sclerenchyma cell with a very thick, hard wall.