Pteronia viscosa, in Afrikaans the gombos (gum bush), is a shrublet with rigid, spreading branches. It grows to 50 cm tall. Gombos is found in the Karoo, the Little Karoo and some inland parts of the Eastern Cape, often in clay soil and quartzite outcrops.
The shrub branches much; the stems grow woody and gnarled with rough grey and whitish bark. Young stems are reddish. The leaves are green, small and thick, opposite, sometimes with small rigid hairs on the margins. The leaf shape is oblong to elliptic with a sharp tip and a central longitudinal groove along the surface. Leaves drop off in dry seasons so that stressed plants show only the younger ones near branchlet ends.
Some say the plant is much browsed by livestock and game, while other records assert that browsing happens only in hard times. However this may be, the plant is more abundant in well managed than overgrazed veld (Vlok and Schutte-Vlok, 2010; Shearing and Van Heerden, 2008; JSTOR).