Tradescantia sillamontana is a perennial evergreen herbaceous plant of the genus Tradescantia. This species is one of the most succulent and xerophytic. It is endemic to dry areas of the State of Nuevo León in northeastern Mexico.
Tradescantia sillamontana has a very recognizable and distinctive appearance. The leaves are arranged in a precise geometric shape. Almost completely white hairs cover all parts of the plant: leaves, shoots, and even the buds. These protect the plant from direct sunlight and excessive evaporation. Shoots and stems reach a height of 30–40 cm, first erect, later prostrate and rooting at the soil surface. The leaves are fleshy, ovate, 3–7 cm long, covered with grayish-white short hairs. During the summer, the flowers appear at apical growth points or in the axils of the bracts; these are typical Tradescantia flowers. The corolla consists of three bright purplish-pink to purple petals and three small sepals.