These pages will give several images of primary growth in cotton stems. Each of these images is labelled in some detail and the page is organized in terms of each tissue system: Dermal, Ground, and Vascular. Within each of these tissue systems, tissues which can be observed in the images will be described.


The epidermis is the tissue found in the outermost layer of cells. This tissue mainly has the function of protecting the stem by secreting the waxy protective layer called the cuticle and from this tissue aerial projections are seen to arise called trichomes. The cuticle is not stained well in the below images but the epidermis and the trichomes are visible.

This cross-section of the stem clearly shows the emergence of a multi-seriate trichome from the epidermal tissue layer. The epidermal tissue and the parenchyma cells in the cortical tissue are present at the top of the image.

This view of isolated trichomes from the cotton stem in polarized light gives a clearer view of their variation in size and length.
To read about primary growth in the ground tissue system...

To read about primary growth in the vascular tissue system...

Introduction | Flowers&Fruit | Roots | Stems | Leaves

© Thomas L. Rost 1998
Section of Plant Biology Division of Biological Sciences