Compilation
Cyathea thomsonii

Trunk erect, to 2.5 m tall and to 15 cm in diameter. Fronds to 2 m long and 80 cm wide; stipe to 30 cm long; basal scales to 20 mm long, dark reddish brown, with narrow thin fringed edges. Lamina elliptic in outline, 2-pinnate to 3-pinnatifid with varying degrees of dissection, to 2 m long, a few pairs of lower pinnae gradually reduced and more widely spaced, lowest 5–12 cm long; largest pinnae commonly 40 cm long, pinnules 10–14 mm apart; largest pinnules commonly to 6 cm long by 1 cm wide, basal 1–4 pairs with stalks less than 1 mm long, the others sessile, lobed to 1 mm from the costa, often some pinnules gradually contracted towards the base, but in all cases the basal pair of lobes conspicuously longer; costules 2.5–3 mm apart: veins commonly 4–5 pairs except in basal lobes, on largest fronds 7–8 pairs, lower ones forked near the costa. Scales and hairs on pinnules: on lower surface of costae many light brown hairs and narrow brown scales, the scales grading distally to hairs; costules and veins bearing pale less contorted to stiff, spreading and almost antrorse hairs on the lower surface. Sori near costules; up to 5 in basal lobes, usually one in each distal lobe, indusia at first forming deep cups with an uneven rim, soon breaking irregularly. Fig. 2: 3, 3A, B (page 10).