These are the flowers of Typha latifolia, the common bulrush, growing vigorously in Lambrok Stream.
The female flowers, densely packed brown florets, are at the bottom and the male flowers, usually a lighter brown, are above. The male flowers in these pictures, having produced their pollen much earlier, have shrivelled away. The female flowers will retain their shape and colour until they burst into masses of fluffy seed during the winter.
Bulrushes grow in or near standing water and are increasingly being used to protect streams and ponds from contamination. They reduce the levels of phosphates, nitrogen and harmful bacteria in the water, and increase oxygen levels; they collect silt and solid detritus around their roots, providing habitat for the sort of bacteria that help break down other contaminants.
There are sites in America where artificial reed-beds, planted with bulrushes (or cattail in American parlance) are being used to filter the toxic acidic runoff from old mines.
If the Wiltshire Housing Site Allocation Plan goes ahead and there is housing development at Church Lane, Upper Studley, and Southwick Court, Lambrok Stream will need protecting from the runoff from the roads, gardens, and roofs of three additional residential sites. If the breeding habitat of the park’s Odonata is not to be damaged, Wiltshire Council should insist that developers include reed-beds in their strategies for protecting the stream.
Pictures by DKG