Crassula pyramidalis

A small succulent from the dry hillsides of South Africa's Western Cape, where it grows in shallow, gritty soil over rock in the Succulent Karoo. Each stem forms a tight, four-sided column of closely stacked leaves — pressed so firmly in four rows that the stem itself is never visible — and can flush red-brown under prolonged sun or drought stress. Note that each column is monocarpic: after producing its cluster of cream-white flowers in late spring, that stem dies back, but the plant persists as new columns emerge from the base. It suits a bright, open terrarium where the soil dries completely between waterings.