by Mary Free and Christa Watters, Extension Master Gardeners
Two words often seen in the description of plant parts, especially stems, leaves, and fruits, are glabrous and glaucous. Glabrous surfaces are smooth and lack hairs, bristles, and glands. Glaucous surfaces have a whitish, gray, or bluish-green coating, sometimes called a bloom. Most conspicuous on fruits, like blueberries and eastern redcedar, blooms are the waxy or powdery coating that tends to rub off. This coating is the outer surface of epidermal cells called the cuticle.
The glaucousness of plants piqued the curiosity of Charles Darwin who studied it off and on for 19 years. To learn more about how Darwin tested a species’ bloom, the benefits of glaucousness to a plant, and which are the glaucous parts of native plants that you might know or grow, click here.
