Drosera xerophila is a perennial herb that arises from dark, sparsely branched, terete roots. Flowering individuals have 8 to 14, spoon-shaped leaves that spread out and lie flat on the ground, forming rosettes that range in diameter from 20 to 50 mm. Older plants can reach up to 20 mm tall by forming a column-like structure with the dried remains of old leaf rosettes stacked up under the current leaves. The new leaves are arranged in a folded manner when young and are bent abruptly like a knee joint. The leaves are bright green to yellowish green, broadly spoon-shaped, rounded, or elliptical, 7–15 mm long and 2–3.5 mm wide at the base, expanding to 5–10 mm at its widest point. The upper surface is covered with with bright red, sticky, radially symmetrical tentacles tipped with mucilaginous glands that secrete a sticky substance. The tentacles at the edge of the leaf are about 0.8–1 mm long with an elliptical gland at the tip and a narrow, flat stalk. The underside of the lamina (leaf blade) has simple, white-translucent hairs that are 0.5–1 mm long. The stipules (small leaf-like structures at the base of the leaf stalk) are very narrow and triangular, 5–6 mm long, and translucent white, turning pale brown when dry. The lower part is entire, while the upper part is divided into three segments, with the middle segment being narrow and triangular, and the lateral segments are linear-triangular. The leaf stalk (petioles) are narrow and wedge-shaped, 3–10 mm long, and about 1 mm wide at the base, gradually widening to 2–3.5 mm. The upper surface of the petiole is smooth, though sometimes it has white hairs. The edges and lower surface of the petiole are densely covered with straight or slightly curled, white-translucent hairs.

The flower stalk (scape) is 100–200 mm long, reddish, and smooth, with some white hairs near the base. The flower-bearing part is covered with small, reddish glands. The inflorescence is a simple, curved cyme with up to 9 flowers, each about 20 mm in diameter, and they bloom one at a time in succession, each lasting for just one day. The flowers have small, glandular hairy bracts, and the flower stalks (pedicels) are 1-5 mm long, extending to 10 mm in fruit. The sepals are 3–4 mm long, elliptic, hairy, and persist in fruit. The petals are light pink to violet-pink, 10–12 mm long, and broadly obovate. The flower has 5 stamens, about 4 mm long, with white filaments that widen at the tips, and yellow, bithecate anthers. The ovary is small and globose, with three fused carpels, and dark pink styles that are bifurcated. The fruit is a dry capsule that splits open when mature, releasing black seeds, 1–1.2 mm long, with a reticulate surface.

Drosera xerophila is winter-growing, flowering in early summer before entering dormancy in summer. It flowers from December to February.

Drosera xerophila is remarkably similar to several rosetted species in its distribution range. Its habitat and colour scheme are quite similar to that of D. esterhuyseniae, which is distinguished by its narrower, elevated leaves as opposed to the flat-lying leaves of D. xerophila. Although it thrives in drier environments, it is typically a brighter matte green, and has a more noticeable petiole. It can also be very similar to D. aliciae var. curviscapa, which ranges from olive green to red, and grows in moister settings, and lacks a visible petiole.