Cyathea cooperi can grow up to 12m in height (Wilson, 2007). The stipe base of Cyathea cooperi has two different types of scales.
The first being dark, small scales and the other being large, pale, papery scales. The latter is the reason for the shaggy blond mat of scales that forms. After the leaves die, the stipes will fall off at the trunk leaving oval scars (Medeiroset al, 1992).
The sorus lacks an indisium and has a ring of small scales around the sporangia (Heenanet al, 1998). The fronds of C. cooperi can grow up to 5m long (Wilson, 2007).
HEAR (2006) states, "Blades 2-pinnate-pinnatifid to 3-pinnate at base, green or light green above, paler below; rachises with dark brown, obtuse tubercles. Pinnae up to 65 x 26cm.
Pinnules stalked, tips acuminate. Ultimate segments deeply pinnatifid to 1-pinnate, segment lobes falcate, margins irregularly toothed or rarely deeply lobed. Veins 1-forked." In older Cyathea cooperi a tight rosette will form at the top of the trunk (Large, 2005).