This perennial herb of coastal grassland occurs in rough grassland and scrubby places adjoining saltmarsh or brackish grazing marsh, on creek sides and on sea walls; also on waste ground and, rarely, on roadsides. Plants spread by rhizomatous growth, but seed ripens only in warm years. Lowland.
This species was recorded in 1666 in Sussex, but has not been seen there subsequently. It appears to have become more frequent in Essex since 1950, though some outlying populations have been lost. Its discovery in 1990 at Southwold, E. Suffolk, is a significant extension of its range.
European Southern-temperate element.
Light (Ellenberg): 7
Moisture (Ellenberg): 5
Reaction (Ellenberg): 8
Nitrogen (Ellenberg): 4
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 4.1
July Mean Temperature (Celsius): 16.7
Annual Precipitation (mm): 599
Count of 10km squares in Great Britain: 10
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: 0.29
RDB Species Accounts
Peucedanum officinale L. (Apiaceae)
Status in Britain: LOWER RISK - Near Threatened.
Status in Europe: Not threatened.
In Britain, P. officinale is exclusively a plant of coastal grassland, from the highest saltmarshes up to, exceptionally, 1.5 km from saline water. It forms conspicuous mounds of ferny foliage amongst coarse grasses such as Arrhenatherum elatius and Elytrigia atherica, but generally dies back to the deep rootstock in winter. In places, it occurs abundantly along the edge of Prunus spinosa, Rosa canina and Rubus fruticosus scrub, where it may benefit from reduced grazing, trampling and mowing. The main habitats are inherently species-poor, although it frequently grows alongside local species such as Genista tinctoria, Ononis spinosa and Trifolium squamosum. Soils are London Clays, boulder clay and recent alluvium (Thornton 1990).
P. officinale is a robust perennial, flowering from July to September. High summer temperatures appear to be required for seed to ripen fully, conditions not occurring every year. Even when seed does ripen, germination is rather patchy, being best where the sward is open and contains bare ground.
It is mainly restricted to two coastal districts in Britain - the north Kent coast from Faversham Creek to Reculver, a distance of some 20 km, and the Walton Backwaters in north-east Essex. Most plants are found on sea-walls and former estuarine land claimed for grazing, apart from one Kent site (Tankerton Cliffs), where it dominates two hectares of unstable cliff-slopes. Because shoots arise from spreading rhizomes, population sizes are difficult to judge. However, the Kent populations are considered to be stable at about 10,000 plants, and Essex is estimated to hold 60% of the total British population, having risen from only 30% of it in the 1970s. Numerically minor localities are Lee-over-Sands (Essex), first reported around 1978, and Southwold, Suffolk, where it was discovered in 1990. The plant was also formerly present in two other Essex estuarine systems (Stour, and Holland Brook) and in West Sussex, where it was recorded in 1666 (Ray 1677) but not subsequently.
Colonies may be damaged by 'engineered' improvements to sea-walls, although disturbance is not always a long-term problem since one of the largest Essex populations is on a former explosives testing site. New coastal defence policies of managed retreat and setting back sea-walls, whilst it may extend the area of saltmarsh, could adversely affect colonies on the front-line defence. Other threats include cliff stabilisation works, and also the mowing of sea-banks, since plants which grow after mowing may flower but do not set seed. P. officinale is the sole larval food plant for two nationally rare moths, a micromoth Agonopteryx putridella and the vulnerable Fisher's Estuarine Moth Gortyna borellii. The latter is found only in the main Essex population, where it was identified in 1970. The mature larvae of G. borellii feed in the rootstock, and a small, but significant threat to the Essex population arises from occasional illegal depredations by unscrupulous moth collectors digging up the plant.
Some doubt has been cast upon the native status of P. officinale, particularly in view of its disjunct distribution with its main sites being near Roman ports. Certainly it has been of economic importance - its roots yield a stimulant resin (Tutin 1980) - and it was considered good fodder for pigs. However Britain may equally be considered a natural outlier of its predominantly continental distribution. In southern Brittany, it is found in similar upper estuarine sites, although further south in Iberia, and eastwards to western Siberia, it occupies a wider range of grassland habitats, up to 1,800 metres in altitude.
Further details are given in Randall & Thornton (1996).
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.
Atlas text references
1978. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols.
1996. Biological Flora of the British Isles. No. 191. Peucedanum officinale L. Journal of Ecology. 84:475-485.
1980. Umbellifers of the British Isles. Botanical Society of the British Isles Handbook no. 2.
1999. British Red Data Books. 1. Vascular plants, edn 3.