Trichodiadema densum is a spreading, mat-forming ground cover type of succulent shrub. It produces abundant large white-centred purplish-pink flowers, blooming at the end of winter in habitat. In cultivation it may, however, be obstinate about flowering. Flowers only open in on sunny mornings for a part of daytime).
The habitat of this plant is arid with extreme temperatures. It lies in the southern Karoo near Willowmore and the eastern Little Karoo around Uniondale. The plant has thick and fleshy tuberous roots. The leaf growth sometimes displays an arrangement in four arrays along the branches. They are browsed by game and livestock in spite of the star-shaped crown of bristles on all the leaf tops, the diadems (Bond and Goldblatt, 1984; www.cactus-art.biz).