THE UBIQUITOUS PARENCHYMA ( now that’s a mouthful !)
Plants contain many types of tissues and within each, various specialized cells – but none of them beat Parenchyma !
These are the biochemistry machines of the plant.
They are alive at maturity (unlike wood) and specialize into many forms.
The basis for all plant function – they are everywhere and in abundance – just like our Garden Care team !!!
In epidermis, some are specialized for light penetration, gas exchange, or defense (hairs). Others control water loss, heat,
and light direction. Specialized cells store sugar, fats, and starches, or secrete oils, nectar and other compounds.
In leaves, the two distinct parenchyma are specialized for light penetration and photosynthesis. They contain large
amounts of chloroplasts. They also assist in regulating gas exchange (carbon dioxide) through Guard Cells (stomata).
Some are also involved in secretion of nectar and manufacturing secondary chemical compounds that act as a protective
material (toxins, oils, gum, alkaloids and irritants). See pictures below from Trinity College.
In many vegetables like potatoes, plantains, legumes and root tubers parenchyma will contain a large amount of starch.
They can also super specialize ! Stellate parenchyma (aerenchyma) in aquatic plants are composed of star-shaped cells
with large air spaces between. The air is what keeps the leaves afloat! Pictures from Cornell University Herbarium.
This post was put together by Peter Morris – our resident Horticulturalist