Tribulus cistoides is a prostrate to ascending perennial herb with several meters long stems. The leaves are compound and opposite, with oblong to elliptic blades measuring (1.5–)3–10 cm in length. Each leaf features 5–10(11) pairs of leaflets 7–28 mm long and 2.5–12 mm wide, characterized by their apiculate or rounded apex. The leaf surfaces are moderately to densely covered with sericeous to long-strigose hairs, while the margins remain entire. It has very short petioles and subulate to falcate stipules 3–9 mm long and 1–4 mm wide. The flowers grow on peduncles that are densely antrorsely strigose and hirsute, with the latter having pustulate bases. These bisexual and actinomorphic (radially symmetric) flowers have a calyx composed of 5 slightly unequal, lanceolate sepals measuring 7–14 mm in length and 2–5 mm in width, with scarious margins. The corolla consists of 5 lemon yellow to bright yellow, deltate–obovate petals, each 11–26 mm long and 6–15 mm wide. The stamens are organized into two whorls of 5, with the outer whorl slightly longer than the inner one, and the anthers are cordate to sagittate. The superior ovary is long–strigose. The fruit is 8–15 mm long, featuring mericarps with dorsal crests and tuberculate surfaces. It is equipped with two stout, hard spines 5–10 mm long and sometimes also with two smaller spines near the base. The crests of the fruit are short and hirsute, with hairs that have pustulate bases. Seeds are oblong and ovoid, with a membranous seed coat, straight embryo, and no endosperm. It is typically found in coastal habitats between 0-50(–100) meters.