Although described as a subspecies of the east Australian C. australis, this plant has been thought by some to be more correctly treated as an endemic Norfolk Is. species.
macarthurii(F.Muell.) Baker J. Bot. 12: 280(1874)
Hemitelia macarthurii F.Muell., Fragm. 8: 176 (Apr. 1874), non Alsophila macarthurii Hook. (1866); Alsophila ferdinandii R.M.Tryon, Contr. Gray Herb. 200: 37 (1970).T: Lord Howe Island, W.Carron & C.Moore; syn: MEL; Lind & J.P.Fullagar; syn: MEL. Named after Sir William Macarthur (1800–1882), an early botanist, horticulturalist and agriculturalist in N.S.W., who did much to establish a wine industry in Australia.
Cyathea moorei Baker in W.J.Hooker & J.G.Baker, Syn. Fil. 2nd edn, 453 (Oct. 1874), non Alsophila moorei J.Sm. (1866).T: Lord Howe Island, C.Moore; holo: K.
Trunk to 4 m or more tall, usually ±shaggy with dark, persistent frond bases, sometimes clear with round scars. Fronds: stipe prickly, with light brown woolly indumentum covered with long, twisted, acuminate brown scales 2–3 cm long; costae glabrous above, with a pale brown, woolly, felt-like indumentum of pale crumpled hairs (easily rubbed off), over a finely warty surface below; lamina bipinnatisect; primary pinnae to 50 cm long, slender-pointed; secondary pinnae 7–11 cm long, 1.5 cm broad; largest pinnules 16–18 pairs, 5–9 mm long, 2–3 mm broad, ±glaucous, shallowly adnate by 0.5 mm on each side of the costae. Sori with saucer-shaped indusia.
L.H.Is.: Mt Lidgbird, C.Moore 29 (K, MEL); E slopes of Mt Lidgbird, P.S.Green 1691 (K); summit of Mt Gower, J.Pickard 3594 (NSW); The Saddle, J.Pickard 3625 (NSW).
Perhaps the commonest tree fern on the Island.
howeanaDomin Pteridophyta 264(1929)
T: as for Hemitelia moorei Baker. Named after Lord Howe Island.
Hemitelia moorei Baker, Gard. Chron. 31: 252 (1872); Cyathea moorei (Baker) F.Muell., Syst. Census Austral. Pl. 137 (1882), nom. illeg. non Baker (1874).T: Lord Howe Island, C.Moore; holo: K.
Illustration: C.J.Goudey, Austral. Fern J. 1:  t. 4 (1984).
Trunk to 3 m tall, with round leaf scars below the crown; stipe bases not persistent. Fronds: stipe with relatively few, caducous brown scales with pale margin and without terminal seta; costae and costules with numerous matted, pale bubble-like bullate scales 0.15–1 mm long, and some short, crumpled hairs below, with dense, long, pale, antrorse hairs above, few or absent on costules; lamina tripinnate; primary pinnae to 35 cm long, relatively shortly acuminate; secondary pinnae 4–7 cm long, 1–2 cm broad; largest pinnules 12–15 pairs, 5–9 mm long, 2–3 mm broad, free, deeply toothed, with teeth acute, usually reflexed. Sori attached on one side, usually enclosed in deflexed pinnule lobes.
Lord Howe Is. Endemic; found on Mts Gower and Lidgbird.
Frequent on the slopes and tops of Mts Gower and Lidgbird.
L.H.Is.: top of Mt Gower, P.S.Green 1597 (K, NSW); Mt Lidgbird, about Round Face, J.Pickard 1449 (NSW); NE flank of Mt Lidgbird, M.M.J. van Balgooy 1146 (NSW); Erskine Valley, A.N.Rodd 1773 (NSW).
The affinity of this species lies, along with others in the Melanesian C. decurrens Copel. group, with Central and South America (see R.E.Holttum, Kew Bull. 37: 383–388, 1982).
brevipinnaBaker ex Benth. Fl. Austral. 7: 709(1878)
Alsophila brevipinna (Baker ex Benth.) R.M.Tryon, Contr. Gray Herb. 200: 36 (1970).T: Lord Howe Island, Lind & J.P.Fullagar; holo: K; iso: MEL, NSW. The name refers to the short (brief) pinnae.
[Cyathea medullaris auct. non (G.Forst.) Sw.: F.J.H. von Mueller, Fragm. 9: 78 (1875)]
Trunk 1.5–3 m tall, with dense, reddish brown scales near top; leaf scars with persistent ±fibrous stipe bases. Fronds: stipe 25–50 cm long, with scales ±persistent, narrow, 2–3 cm long, with a fine tip, dark brown with a lighter edge, warty below; costae and costules glabrescent below except for scattered warty bases of early shed scales, somewhat prickly, with antrorse hairs above, few or absent on costules; lamina tripinnate; primary pinnae to 20 cm long; secondary pinnae 3–5 cm long, 1–1.2 cm broad; largest pinnules 10–15 pairs, 5–6 mm long, 2–5 mm broad, free; fertile pinnules deeply divided, with divisions rounded-crenate and curled over sori. Sori attached on one side, with large, persistent indusia.
Lord Howe Is. Endemic; on the higher parts of Mt Gower (and presumably Mt Lidgbird, but no collections or records have been seen from there).