Eriocaulon  (Eriocaulon asteroides)

This tiny herb has short, linear leaves that taper to a point and are arranged in rose-like clusters (2). The flower head, or capitulum, is around 5 to 7 millimetres wide and contains a small number of star-like flowers (2).

Eriocaulon asteroides is known from six locations in Nigeria and Cameroon, in West Africa (1).

Found on thin, peaty, seasonally waterlogged soil in the cracks between blocks of basalt; a habitat known as 'basalt pavement' (3). Usually associated with the bladderwort Utricularia scandens, and grasses and sedges such as Loudetia simplex and Scleria interrupta, at altitudes of between 1,700 and 2,500 metres above sea level (3).

This herb is an annual, and therefore grows for just one year (2). It is often found at the same site as Eriocaulon parvulum, which is superficially similar in appearance (3).

Ericocaulon asteroides is considered to be Vulnerable (1), but the precise threats to its survival have not been identified. It is likely that heavy trampling by cattle on the thin soil may damage these plants by dislodging them (3). However, without some level of grazing or of grassland fires, soil can build up, and this will in turn allow grasses such as Sporobolus spp. to encroach and smother, or compete with, the small E. asteroides (3).

Surveys to discover additional populations in the Kilum-Ijim area, as well as more detailed information on existing known populations are urgently required (3). In addition, experiments to investigate the optimum level of cattle grazing and bush fires may be needed in order to guide habitat management plans (3).

Authenticated by Ben Pollard, Royal Botanic Gardens, Kew.
http://www.rbgkew.org.uk