Corrigiola litoralis L.

Strapwort rarely overwinters and forms a flat rosette of several low, radiating shoots. The tiny whitish-green flowers appear in late July or August. They are self pollinating and fertilisation often occurs whilst the flower is still closed, a process known as cleistogammy. The plant reproduces entirely by seed.

English Nature included strapwort in its Species Recovery Programme in 1991. A three-year plan was initiated at Slapton Ley, beginning with the removal of encroaching willow and the re-introduction of cattle grazing to the lagoon shoreline. Further work on shoreline management is on-going, as the low populations can be attributed to the failure of past management methods. The outfall sluice, whilst cleared periodically of storm-driven shingle, could not be relied upon to control the water levels in the lagoon. The outfall sluice has been replaced with a fixed weir, but the outfall itself becomes blocked during easterly storms reducing draw-down. Neither of these situations is ideal, so if shoreline management alone is insufficient to ensure the maintenance of a viable population, then the outfall options will have to be reconsidered. Seed collected from the site was successfully germinated by the Royal Botanic Gardens, Kew, and plant re-introductions have taken place regularly at Slapton Ley. When suitable conditions have been re-created at Loe Pool in Cornwall, it is intended to re-introduce strapwort back this former site. Efforts to save this interesting species in England will continue. Water quality is regularly monitored as well as the all important water levels but, inevitably, future re-introductions will almost certainly be needed again.

Strapwort is a small, branched, annual plant, usually found along muddy lake shores. The stems of the plant are reddish in colour and the leaves are long and oval in shape, widest near the tip. The flowers are tiny, only 2 mm across, and whitish-green.

The only UK site where strapwort occurs now is at Slapton Ley, a coastal lagoon in Devon. Here, muddy shingle is seasonally inundated by water and trampled by cattle coming to drink, conditions which seem to suit the plant.

Western and southern Europe, extending northward to Britain and Denmark, but the plant is in decline. In Britain it used to occur on just two sites, one in Devon and one in Cornwall. However, the plant disappeared from the Cornish site in the early part of the 20th century. Strapwort is also found in Russia, Turkey and widely in Africa where it occurs on a variety of habitats. This apparent adaptability makes it difficult to account for the rarity of the plant in the UK.

Classified as Critically Endangered in the UK.

This plant is non-competitive and is intolerant of competing vegetation taller than 4 cm. It prefers open ground which is seasonally covered by water and poached by cattle. The few places where the plant used to occur have lost their suitability during the last 100 years and the former Cornish site at Loe Pool, is regarded as unsuitable for re-introduction. The plant has declined in numbers at Slapton Ley, its Devon site, since the 1960s; fluctuating water levels plus a lack of cattle grazing are thought to be responsible. In 1993 no plants were recorded although 11 appeared the following year adjacent to a newly created livestock watering area. The vital catalyst in the decline of strapwort appears to be the loss of muddy shingle seasonally inundated by water, which effectively removes competing vegetation and leaves the gravelly conditions required for germination. Unfortunately, at Slapton Ley, storm-driven shingle has blocked the outfall sluice from the lagoon, slowing down the natural drop in water levels and reducing the amount of exposed shoreline.