Inflorescences spicate, globose, ovoid, ± cylindrical or rarely interrupted, mostly terminal, occasionally also axillary, axis woolly. Bracts persistent, scarious, glabrous or variously hairy, the midvein frequently excurrent. Perianth segments 5, fused for a short distance from the base, variously hairy. Stamens 5, frequently 1–3 reduced to staminodes; filaments usually slightly shorter than perianth segments, usually fused at the base into a membranous cup, occasionally with small teeth alternating with the filaments. Ovary sessile or shortly stipitate; ovule 1, pendulous.
| | Key to the species | |
| 1 | Inflorescence cylindrical | 2 |
| Inflorescence globose or ovoid | 11 |
| 2 | Leaves (and stems) hairy, especially when young | 3 |
| Leaves glabrous, stems mostly glabrous
Back to 1 | 6 |
| 3 | Inflorescences less than 5 cm long | 4 |
| Inflorescences, or at least some of them, more than 5 cm long
Back to 2 | 5 |
| 4 | Leaves oblanceolate, 1.5–2.5 cm long, 3–4 mm wide; hairs simple | Ptilotus indivisus |
| Leaves obovate, 1–4 cm long, 5–20 mm wide; hairs stellate and simple
Back to 3 | Ptilotus obovatus |
| 5 | Inflorescence more than 2 cm diam., dense | Ptilotus polystachyus |
| Inflorescence less than 2 cm diam., interrupted
Back to 3 | Ptilotus extenuatus |
| 6 | Inflorescence more than 3 cm diam | 7 |
| Inflorescence less than 2.5 cm diam
Back to 2 | 9 |
| 7 | Leaves narrow-linear, c. 3 mm wide | Ptilotus macrocephalus |
| Leaves obovate or oblong-lanceolate, more than 20 mm wide
Back to 6 | 8 |
| 8 | Inflorescence yellow-green; leaves mucronate or entire | Ptilotus nobilis |
| Inflorescence pink-purplish; leaves acute
Back to 7 | Ptilotus exaltatus |
| 9 | Leaves spathulate, ovate-cuneate or lanceolate | Ptilotus spathulatus |
| Cauline leaves linear or linear-lanceolate
Back to 6 | 10 |
| 10 | Inflorescence yellow-green; perianth segments 6–12 mm long, acute | Ptilotus gaudichaudii |
| Inflorescence mauve or pinkish; perianth segments less than 6 mm long, obtuse
Back to 9 | Ptilotus leucocoma |
| 11 | Leaves (and stems) hairy, especially when young | 12 |
| Leaves glabrous, stems mostly glabrous
Back to 1 | 16 |
| 12 | Simple and either stellate or dendritic hairs present on leaf | 13 |
| All hairs simple
Back to 11 | 14 |
| 13 | Perianth segments 6–10 mm long, inner surface glabrous | Ptilotus obovatus |
| Perianth segments 11–13 mm long, inner surface woolly at the base, with scattered hairs above
Back to 12 | Ptilotus sessilifolius |
| 14 | Leaves obovate | Ptilotus latifolius |
| Leaves broad-lanceolate or linear
Back to 12 | 15 |
| 15 | Basal leaves broad-lanceolate, `petioles' winged | Ptilotus seminudus |
| Leaves linear to broad-linear, petioles not winged
Back to 14 | Ptilotus erubescens |
| 16 | Leaves less than 10 mm long | Ptilotus remotiflorus |
| Leaves more than 10 mm long
Back to 11 | 17 |
| 17 | Perianth segments more than 12 mm long | 18 |
| Perianth segments less than 12 mm long
Back to 16 | 20 |
| 18 | Leaves broad-lanceolate | Ptilotus seminudus |
| Leaves linear or linear-lanceolate
Back to 17 | 19 |
| 19 | Margins of cauline leaves undulate | Ptilotus semilanatus |
| Margins of cauline leaves flat and entire
Back to 18 | Ptilotus erubescens |
| 20 | Perianth segments acute, 6–12 mm long; inflorescence greenish yellow | Ptilotus gaudichaudii |
| Perianth segments obtuse, 6 mm or less long; inflorescence mauve or pinkish
Back to 17 | Ptilotus leucocoma |
