This plant is not yet visible in the Garden.
The most striking feature of the Blue Oil Fern is the iridescent colour to the leaves. Researchers in the Department of Chemistry have found that the blue colour is caused by fibres of a chemical called cellulose in the cell walls in the leaves. These fibres pack like plywood and interact with light to reflect intense blue and green colours. Interestingly, the fibres on the underside of the leaf are arranged in a slightly different way to those on the top, so the underside shimmers greeny-red, while the top is metallic blue.
At present, the reason why the Blue Oil Fern has iridescent leaves is a mystery. It is possible that the iridescence on the top surface of the leaf is how the plant protects itself against high light levels, while the iridescent underside reflects light which has travelled through the leaf, improving the efficiency of photosynthesis.