Cross-section of leaf stalk (approx 17mm x 12mm).
The large spear-shaped leaf stands over 90cm high, of which about 30cm is the stiff blade. This is supported on an extremely strong and stiff petiole, whose nearly cylindrical, internally strutted construction forms the pattern.
The lower part of the 'cylinder' is formed by the inrolled edges of the petiole, which overlap in the section. Most of the strength is provided by fibres just under the skin of the petiole.