Pygmy rush  (Juncus pygmaeus)

Classified as Endangered in the UK.

One of our smallest members of the rush family, pygmy rush has one or a few flower heads, each with one to five flowers. The leaves at the base of the plants are thread-like, only one millimetre wide. Plants are green, but often become suffused with pink or purple in early summer.

Pygmy rush is an uncommon species found in southern and western Europe, northwards to Denmark and eastwards to Italy, Yugoslavia and Turkey; also in north west Africa. In Britain it has always been restricted to the Lizard Peninsula in Cornwall.

You can view distribution information for this species at the National Biodiversity Network Gateway.

This species prefers intermittently flooded sandy and peaty sites, such as along rutted tracks and around gateways. It requires frequent disturbance of the ground, of the sort created by cattle trampling, or repeated rutting by vehicles.

Pygmy rush is an annual, unlike most of the rush family which are perennials. The plants germinate in spring as water levels decline, maturing on exposed mud in early summer, usually June. Numbers of plants fluctuate wildly from year to year depending on the timing of the drop in water level and on the density of cover of other competing vegetation.

As one of Britain's rarest and most threatened plants, the decline of pygmy rush has been the subject of much study and speculation. Its decline has principally been the result of changing farm management and, in particular, the maintenance (or otherwise) of the Lizard's rutted tracks and gateways. Some tracks have fallen into disuse, while others have been upgraded, with deep, seasonally-flooded ruts and depressions being infilled with hardcore. Several of its sites have been lost in this way in recent years, and pygmy rush is now reckoned to be one of the most threatened of the Lizard's special plants.

Pygmy rush is listed in the UK Biodiversity Action Plans (UKBAPs), and included in English Nature's Species Recovery Programme (SRP). As with all rare species, the first priority in conserving pygmy rush is to ensure that the few remaining extant populations do not disappear. Fortunately, several colonies lie within Sites of Special Scientific Interest and the Lizard National Nature Reserve.

A number of tasks have been identified in the Action Plan to save the pygmy rush. Landowners on the Lizard are being encouraged to continue managing their tracks and gateways in appropriate ways, and money from the Countryside Stewardship Scheme is available to fund this.

In view of its extreme vulnerability, seeds from some of the remaining populations have been stored in the Millennium Seed Bank run by the Royal Botanic Gardens, Kew. This safeguards against the total loss of the species in the wild, as seed from this collection could be used in some future re-introduction process. Hopefully, this last action will not be needed for pygmy rush: with the support of land managers on the Lizard, and with an understanding of its very particular habitat requirements, it is anticipated that this rare and intriguing rush will maintain its toehold as a wild plant in Britain.

The UK Biodiversity Action Plan for this species is available at UK BAP.

There may be further information about this species available via the National Biodiversity Network Gateway.