The leaf column of Crassula plegmatoides looks like craftily plaited bead-work. Seasonal leaf colour changes between grey-green and pale pink reflect responses to rainy winters when the plant grows or dry summers when the plant rests. The outer leaf surface is rounded, egg-shaped, while the inner, upper surface is concave, for close stem-hugging in the neatly fitting columnar mode.
The four leaf arrays bring about a four-angled or square (in cross-section) appearance. Within this succulent armour the stem itself is well hidden from its tip to the ground, or to where old dry leaves persist lower down. There are hairs on the leaf margins and a slightly pointed leaf tip.
The species resembles C. columella, and to some extent C. deceptor (Le Roux, et al, 2005; iNaturalist).