Trichodiadema marlothii is succulent plant of the genus Trichodiadema, native to the Western Cape Province, South Africa, where it is known from the Robertson and Swellendam areas.

The leaves are papillate and each is tipped with 5-10 large, white, radiating bristles (diadems), that are parted and spread out in two directions.

The fruit capsule has six locules, each with very well developed covering membranes.

This species very closely resembles Trichodiadema hirsutum, which differs only in having a larger number of bristles, 20(-40), on its leaf tips.

[1] This species also somewhat resembles Trichodiadema emarginatum, which however has five locules, an even lower growth-habit and petals that are emarginate.