News from the Riverside – July 2019:
We all know that plants are important and yet we are witnessing real declines in many plant species driven by changes in land management. When species are widely distributed localised disasters such as disease, predation or habitat change have little effect on the overall population. Once habitats become seriously fragmented, however, species can become isolated and then when any of the above factors arise they can disappear and another step is taken along the path to extinction.
The Deptford Pink is one such species which in Great Britain is described by the Wildlife Trusts as being ‘very localised and rare’. It is red listed and is at high risk of extinction. Once common, the pink’s decline has been precipitous and in the east of England it is almost as rare as hen’s teeth. Nationally about fifteen sites remain. Causes for this decline are cited as loss of dry pasture land and other suitable habitats such as tracks and unsprayed field margins. Indeed, through the twentieth century enormous changes in the way our countryside was managed led to fragmentation and loss of semi-natural habitats.
The Deptford Pink can still be found on the Valley Trail but it was once much more widespread as it was recorded at seventeen local sites. By 2011 it was down to a single site where there were only ten plants. Having established that it is an exceedingly rare species, its Sudbury site is clearly important and in recent years considerable work has been carried out to improve the habitat to suit it. It dislikes competition so the removal of soil nutrients and aggressive competitors are essential.
The plant produces deep pink blooms, splashed with small white dots and although the flowers are extremely pretty they open sporadically two or three at a time and are easily overlooked. It is a difficult flower to find and this is not helped by the fact that the blooms close as the afternoons advance. The main flowering period is through late June and July although occasional blooms continue to open throughout late summer and into autumn. At its Sudbury site it is strictly biennial, forming a rosette of leaves in its first year and producing flowering stems in its second year before withering away. It is capable of producing masses of seeds but both the flower stalks and the seed pods are extremely palatable to birds and animals and are very often eaten off which seriously compounds the problem of its survival. Only very careful intervention and support will ensure its continued existence at that site. This year voles have gained access to the protective pound and have eaten off most of the stems ahead of flowering.
Clearly the Deptford Pink is a very rare plant in need of help but it is easily confused. Some people have suggested that it grows all over the adjacent horse paddocks. If that were the case, then continued high level intervention at its only site in the region would be unnecessary and the job would be done. However, the plant that ‘citizen scientists’ see in the paddocks is common centaury which is, as the name suggests, extremely common. Superficially it does look similar to the pink although shorter but with similar shaped flowers and seed heads. The Deptford pink, however, is a dianthus while common centaury belongs to the gentian family.
Adrian Walters (Clerk to the Trustees of the Sudbury Common Lands Charity and Ranger)