A slender, geophytic herb, up to 750 mm high. The root is tuberous. The stem is simple and harshly hairy. Leaves are simple, narrow and hairy with the blade 76–152 × 3–10 mm. The margins are rolled in below and have prominent veins below. The petiole is very short, less than 6 mm long.

The inflorescence is large, up to 114 mm long, solitary, hanging or nodding with 3–5 flowers per umbel. The calyx is acute, broad and lance-shaped, up to 10–19 × 4–6 mm. The corolla is globose, with a diameter of 24–50 mm, pale green, dull cream-green, becoming brown with age and coarsely pubescent. The pedicels that attach the inflorescence to the stem are subscabrous (rough) to pubescent, up to 19–38 mm long. The peduncles that attach the flowers to the pedicel are 19–32 mm long.

Figure 2. Pachycarpus campanulatus var. campanulatus showing the corona lobes stretching from the centre to the rim of the corolla. (Photo: Adam Shuttleworth)

The corona lobes (7–16 mm long), are linear to lanceolate, spreading and reaching the rim of the corolla; the keels are paired and obliquely deltoid.

Figure 3. Central gynostegial column which consists of the fused anthers, style and stigma and keels of the corona.

The pollinia are narrowly pear-shaped. The bracts are broad, linear to linear-lanceolate, 12–16 × ± 2 mm. The fruits are fleshy and seeds are bifacial, with one side slightly concave. The anther appendages are 3–4 mm long. The style apex is crater-like. This species flowers in summer, from November to February.

Figure 4. The pollination unit consisting of a clip that attaches to the pollinator and the pollen gathered in 2 sacs (pollinia).