The genus Cyathia has over 550 species with 11 or 12 found in Australia.
There are also varieties in some species.
They are divided into 2 subgroups.
1. In Cyathea subgen. Cyathea, the bases of the frond stalks have scales that are dark black or brown,
thicker in the middle, thin at the margin and usually without spines.
The marginal cells are oriented in all directions.
Australian species are C. australis, C. baileyana, C. cunninghamii, C. rebeccae, C. robertsiana and C. woollsiana.
2. In Cyathea subgen. Sphaeropteris the scales are usually thin and pale, with reddish-brown marginal spines.
Their cells are all orientated towards the tip.
There are also some smaller red scales.
Australian species are
- C. celebica (lower leaflet surface covered with a network of white hairs),
- C. celina (swollen bladder-like scales),
- C. cooperi (small scales never swollen) and
- C. leichhardtiana (black stalk and midrib with spines).