Monday 20 August 2007

Floral freeloader

It looks like a fungus growing among the leaf litter on the forest floor but the closest of close ups reveals thousands of tiny white flowers clustered together where there should be a fungal cap. Balanophora fungosa is a flowering plant that has abandoned photosynthesis and adopted a parasitic lifestyle. Instead of using light energy to manufacture sugars from carbon dioxide and water, Balanophora taps into those already made by a host tree. Having ditched photosynthesis, there is no need for chlorophyll — the plant comes in a range of earthy colours but none of them is green.

For most of the year, Balanophora lives entirely in the soil. In winter, the flowering heads push up through the humus. At this time, the forest floor can be packed with these low-profile plants but fallen leaves may hide them from view.


Balanophora fungosa in rainforest at Lake Eacham. The flowering heads are covered by scale-like leaves.




Balanophora fungosa at the Hinchinbrook Island lookout. Female flowers are clustered on the golf ball* inflorescences, whereas male flowers project from the base.

Southern Illinois University's Parasitic Plant Connection has more photos of this species and its relatives.
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* May not be a strictly technical term.