Stipe of fronds yellowish to brown to dark red-brown or almost black, often bearing short, sharp spines; lamina broad-lanceolate, 2-pinnate or more compound, usually leathery, bearing small scales along the axes.
| | Key to the species | |
| KEY TO THE NSW MAINLAND SPECIES | |
| 1 | Scales on stipe base dark brown or brown with pale margins | 2 |
| Scales on stipe base predominantly pale with dark spinules along the margins | 3 |
| 2 | Scales of trunk and stipe base shiny, red-brown, stiff and often twisted, 2–5 cm long, with inconspicuous pale fragile edges | Cyathea australis |
| Scales of trunk and stipe base dull pale brown to dark brown, to 3.5 cm long, with a conspicuous pale margin
Back to 1 | Cyathea cunninghamii |
| 3 | Stipes dark brown to black, prickly, the bases persistent on the trunk; scales of stipe base very pale, to 6 cm long and 1 mm wide | Cyathea leichhardtiana |
| Stipes yellowish brown to brown, warty, the bases deciduous; scales of the stipe base of two kinds, pale and 2–5 cm long and 0.5–5 mm wide, and inconspicuous red-brown scales 0.5–1.5 cm long and to 0.5 mm wide
Back to 1 | Cyathea cooperi |
| KEY TO THE LORD HOWE ISLAND SPECIES | |
| 1 | Pinnules in the central portion of the pinnae 7–14 cm long, with 16–20 opposite pairs, before they diminish markedly in size towards the long pointed apex | 2 |
| Pinnules in central portion of pinnae 3–7 cm long, with 10–15 lamina segments, before dimishing in size towards the apex | 3 |
| 2 | Lower surface of costae and costules with small scattered bubble-like scales; pinnules deeply toothed with acute teeth deflexed around sori | Cyathea howeana |
| Lower surface of costae and costules without scales, prickly with the bases of earlier shed scales; pinnules more or less entire except where fertile; fertile pinnules deeply toothed, with rounded teeth around sori
Back to 1 | Cyathea brevipinna |
| 3 | Fertile pinnules deeply pinnatisect, the divisions in the centre of the pinnule joined basally along the costa by 0.5–1 mm of continuous lamina | 4 |
| Fertile pinnules completely pinnatifid, the divisions in the centre of the pinnules not joined by any continuous lamina at their base
Back to 1 | Cyathea robusta |
| 4 | Stipe and primary rachis with a mixture of scales and crumpled hairs, but scarcely a felted indumentum | Cyathea australis |
| Stipe and primary rachis with a felted indumentum of crumpled hairs
Back to 3 | Cyathea macarthurii |
