An annual of coastal rocks and eroding sea-cliff edges below maritime Calluna vulgaris-Empetrum nigrum heath. Plantago spp., particularly P. maritima, are constant associates and may act as hosts. Lowland.
This tetraploid species was first described in 1929, and despite its relative distinctiveness, past confusion with other species and current under-recording make it difficult to assess changes in distribution. However, populations appear to be relatively stable with only limited losses through cultivation of cliff-tops. In more basic situations, E. marshallii is often replaced by its hybrid with E. nemorosa. There are many more recent records than when mapped by Wigginton (1999).
Light (Ellenberg): 8
Moisture (Ellenberg): 5
Reaction (Ellenberg): 6
Nitrogen (Ellenberg): 3
Salt Tolerance (Ellenberg): 1
January Mean Temperature (Celsius): 3.8
July Mean Temperature (Celsius): 12.3
Annual Precipitation (mm): 1334
Count of 10km squares in Great Britain: 39
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
RDB Species Accounts
Euphrasia marshallii Pugsley (Scrophulariaceae)
Eyebright, Lus nan Leac
Status in Britain: LOWER RISK - Near Threatened. ENDEMIC.
This is a strictly coastal plant of rocks and eroding sea-cliff edges, primarily of the northern and north-western Scottish mainland, with a few localities in the islands, southwards to Skye and northwards to Shetland. However, a number of past records, particularly from Orkney and Shetland, refer to other taxa (Stewart, et al. 1994). It often occurs in moderately basic sites, with such species as Anthyllis vulneraria ssp. lapponica, Carex capillaris, Coeloglossum viride, Gentianella amarella ssp. septentrionalis, G. campestris, Oxytropis halleri and Scilla verna, but may be more typical of leached or less basic sites below maritime Calluna - Empetrum heath, with Festuca rubra, Plantago coronopus and Thymus polytrichus. Plantago maritima is a characteristic associate and seems likely to be a regular host. E. marshallii occupies equivalent habitats to E. ostenfeldii further north (Shetland and Faeroe Islands) and E. tetraquetra to the south, growing and hybridising with the latter species on Skye.
Although long known to botanists who explored the north coast, it was confused with quite unrelated taxa until described as a separate species by Pugsley in 1929. Despite continuing confusion, notably with E. ostenfeldii, it is a distinctive taxon, well delimited within its main range.
It appears to be regularly outcrossing and hybridises readily with other species. Where it grows close to cultivated areas, there may be substantial gene flow from E. arctica, at times causing considerable morphological modifications of populations. On dunes and basic cliffs, it may be entirely replaced by its hybrid with E. nemorosa. This hybrid is very locally abundant on Lewis, and pure E. marshallii requires modern confirmation. Other hybrid populations are usually of more limited extent.
Taxonomic confusion with other hairy taxa and lack of detailed monitoring make it difficult to assess any changes in distribution. However, populations appear to be relatively stable and there have been only limited losses, primarily through cultivation of cliff-tops. It requires rediscovery in some former localities, but a decline in modern records is primarily indicative of greater taxonomic insight. It is reasonable to suppose that further populations await discovery on the more remote parts of the north coast.
A. J. Silverside
Scarce Atlas Account
Euphrasia marshallii Pugsley
This is a strictly coastal plant of rocks and eroding sea-cliff edges, often on moderately basic sites, with such species as Carex capillaris, Coeloglossum viride, Gentianella amarella subsp. septentrionalis, Gentianella campestris, Oxytropis halleri and Scilla verna. However, the most characteristic plants are found in rather leached or less basic sites below maritime Calluna-Empetrum heath, with Festuca rubra, Plantago spp. and Thymus polytrichus. It occupies equivalent habitats to E. ostenfeldii further north and E. tetraquetra to the south, growing and hybridising with the latter species on Skye. It is confined to the lowlands.
E. marshallii is a hemiparasitic annual, presumably germinating in spring and attaching to a suitable host when root contact is first made. No information is available on host plants, but it is unlikely to be host specific. It commonly occurs in very close association with Plantago maritima and it has also been observed growing with P. lanceolata in the apparent absence of other vascular plants, P. lanceolata being a generally suitable host for Euphrasia spp. in cultivation.
Taxonomic confusion with other hairy taxa and lack of detailed monitoring make it difficult to assess any changes in distribution. The majority of past records from Orkney and Shetland are suspect, especially those made as "E, marshallii var. pygmaea", which are mostly referable to E. foulaensis x ostenfeldii or to E. ostenfeldii itself. E. marshallii hybridises readily with E. arctica, and since the latter becomes an invasive grassland species in the north, cultivation of cliff tops for hay has led to genetic alterations in adjacent E, marshallii populations. On dunes and limestone cliffs, or where cliffs have been enriched by blown shell sand, E. marshallii is often replaced by its hybrid with E. nemorosa. Impressions suggest that these are serious threats to the species, but most collecting and fieldwork has been done at the most accessible parts of the coastline, where these threats are at their greatest. There are many miles of unsurveyed and apparently suitable cliff habitat away from these influences, E. marshallii is endemic to Britain.
As this species has been recorded in only 15 British 10 km squares since 1970, it qualifies for inclusion in the Red Data Book (Perring & Farrell 1983) under the current criteria. However, it will probably be recorded in more than 15 British 10 km squares when, as seems likely, it is refound in some of its old localities.
A. J. Silverside
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.