BSBI Species Accounts ArchiveCarex maritima
Tue, 08/24/2010 - 13:19 | 
markd
The name Carex maritima Gunnerus is accepted by all authorities (Sell 1996; Stace 1997), and antedates the synonym C. incurva Lightf. Its common name is Curved Sedge.
Chromosome No.: 2n = 60 (Stace 2010).
Photograph: A.J. Lockton.
In the British Isles this species is now entirely restricted to Scotland. It used to occur in two places on the Northumberland coast but it has not been seen at either for some time. Some maps show dots on the coast of Lancashire and Cumbria but these are now thought to have been errors. There is a widespread perception (e.g. Preston, Pearman & Dines 2002) that Carex maritima is declining dramatically, but recent surveys by the BSBI have shown that it is still more widespread than was believed (Jermy et al. 2007). The problem with targeted survey like this, however, is that the extra recording effort creates a bias in the data, meaning that any comparisons are open to some doubt. Certainly there are more sites now known for it than ever before, and it is thriving in many of those sites, but that does not necessarily mean that it is increasing. It is widely distributed throughout the sub-arctic region, on coastal dunes and on mountains such as the Alps, Caucasus, Himalaya, Rockies and Andes (David 1982). It also occurs on coasts in the southern hemisphere (David in Stewart, Pearman & Preston 1994).
Photograph: A.J. Lockton.
Click on the map to view full-size on the BSBI Maps Scheme website.
Origin: native in Britain, although some populations inland are accidental introductions.
Rarity: Nationally Scarce in Britain (Stewart, Pearman & Preston 1994), but extinct in England and absent from Wales and Ireland.
Threat: currently classified as Endangered (Cheffings & Farrell 2005), but if it is not declining it would be more appropriately listed as “Least Concern.”
Conservation: all recorders regard it as an axiophyte, being an indicator of active dune systems. Sometimes it occurs on golf courses and airfields, where it is short-lived and has presumably been spread by mechanical means, and in these situations it is of less value as an ecological indicator.
David (1982) describes four habitats for it in Britain: on open, damp sand; at the mouth of a stream debouching on to a beach; in wet dune slacks; and in turf beside rock pools. It is tolerant of erosion but can stand little competition from other plants (David in Stewart, Pearman & Preston 1994). It reproduces vegetatively by deeply-rooted rhizomes and can form extensive stands quite rapidly. It seems likely that it is a vigorous coloniser, able to exploit available eroded habitats when they become available. By contrast, there are numerous instances of it disappearing from closed swards or successional vegetation communities. C. maritima plants can produce abundant large fruits which may be adapted to long periods of dormancy. The existence of a large viable seedbank may be the reason why it sometimes appears in huge numbers in dune slacks, golf courses, airfields and quarry floors, only to disappear completely after a few years. It is also known to crop up in sand dumped by roadsides or used in inland construction projects but, again, it doesn’t tend to last long. Rodwell (2000) gives no NVC communities for Carex maritima, but in the new Sedge Handbook Jermy et al. (2007) suggest that it occurs in communities ‘such as’ SM16 Festuca rubra and SM19 Blysmus rufus saltmarsh.
Photograph: A.J. Lockton.
To know how C. maritima is faring in the long term, we need to how many sustainable ‘natural’ sites there are - the ones by streams in dune systems, and how many temporary ‘un-natural’ sites there are. This situation is complicated by the fact that some of the temporary sites, such as dune slacks, may be part of the natural cycle. In essence, the key question about C. maritima is: ‘Is the seedbank increasing or decreasing?’ But we have no direct way to measure that. Potential threats to this species include coastal erosion, sea-level rise, and development in coastal areas. Drainage and agricultural improvement of coastal grasslands could threaten sites, as could a change in rainfall patterns as a consequence of climate change. On the other hand, several of these factors could work to increase populations and create new sites. Continued detailed recording is needed before any of these questions can be answered. Another question of interest is why it is not found on the west coast of Scotland. One theory that has been put forward is that it cannot adapt to falling sea levels, whereas it can stand rising ones (the west coast of Scotland is slowly rising by isostatic rebound, following the last Ice Age). There is no way of testing this theory yet, but perhaps similar conditions occur elsewhere.
- David, R.W. 1982. The distribution of Carex maritima Gunn. in Britain. Watsonia 14, 178-180.
- Jermy, C., Simpson, D., Foley, M. & Porter, M. 2007. Sedges of the British Isles, 3rd ed. Botanical Society of the British Isles, London.
- Lockton, A., Pearman, D. & Metherell, C. 2009. Is Carex maritima extinct in England? BSBI Recorder 13, 10-11.
- Pearman, D. & Lockton, A. 2007. Progress with the Carex maritima survey. BSBI Recorder 11, 11-12.
- Pearman, D. & Lockton, A. 2008. Carex maritima update. BSBI Recorder 12, 11.
Tags: Sand dunes
Eryngium campestre
Wed, 08/11/2010 - 12:05 | markd
Eryngium campestre (L.), Field Eryngo, is distinctive member of the Apiaceae and is an uncontroversial taxon. It has local names of Daneweed, Watling Street Thistle, Hundred Headed Thistle and, in Wales, Ysgallen Ganpen. It is one of five species of Eryngo which are known to occur in Britain (Stace 1997). There are no known synonyms for this species or information on hybridisation.
Chromosome No.: 2n = 14, 28 (Stace 2010).
Photograph:M. Ingram
It is a rigid, pale green,glabrous, branched perennial that grows up to 75 cm high and has distinctive spiny leaves and ovoid umbels. It is superficially similar to E. maritimum and the two can occur together e.g. in sand dune habitats, but the latter species is often smaller with a blue capitulum rather than green in E. campestre.
It is native to Spain, France, Germany and Greece and other scattered localities in Europe, and is also found in Africa and Asia.
In Britain there are sites in Cornwall, Devon, Somerset and Kent, and it has been recorded as far north as Northumberland, in Wales and in Southern Ireland (Preston et al. 2002).
Click on the map to view full-size on the BSBI Maps Scheme website.
In Britain E. campestre is currently considered to be an archaeophyte (Preston et al. 2002), but it has been thought to be possibly native in Kent and Devon (Stace 1997). It was first recorded in 1662 by John Ray in Devon.
It is a rare plant in Britain being recorded in just twelve 10 km squares in the period 1987-99 (Preston et al. 2002), and is listed in the British Red Data Book as Critically Endangered (Cheffings & Farrell 2005), but with the comment ‘cannot distinguish between casuals and established sites.’
In Europe it is often common and locally abundant and sometimes considered an agricultural weed (Salva and Bermejo 1987).
E. campestre is a plant of dry, open grassland but also disturbed habitats such as waste places and roadsides and often shows a preference for calcareous soils (Stace 1997). The sites in Devon include semi-improved and improved grassland on acidic soils as well as disturbed areas (Ingram 2007).
It is not mentioned as a component of any grassland or other open habitat National Vegetation Community (Rodwell 1991-2000), nor in earlier works on vegetation communities (e.g. Tansley 1939).
It is a hemicryptophyte perennial and is insect pollinated, but has also been noted to reproduce vegetatively (Ingram 2007). It flowers from July to September.
Whether this species should be considered native in Britain or not is open to question.
Studies of its genetics in relation to populations on the continent might help to determine the origin of the plant in Britain.
In Southern Europe there are known parasitoids of E. campestre (Kaydan et al. 2006) which, if also found in Britain, might help to confirm native status (Preston 1986). It would also be useful to know if it occurs in any semi-natural vegetation communities.
- Ingram, M. 2007. The Management of Eryngium campestre at Scabbacombe, South Devon. National Trust.
- Kaydan, M.B., Kilincer, N., Uygun, N., Japoshvilli, G. & Gaiman, S. 2006. Parasitoids and Predators of Pseudococcidae (Hemiptera: Coccoidea) in Ankara, Turkey. Phytoparasitica 34, 331-337.
- Preston, C.D. 1986. An additional criteria for assessing native status. Watsonia 16, p83.
- Salva, A.P. and Bermejo, J.E.H. 1987. Floristic composition and agricultural importance of weeds in Southern Spain. Weed Research 28, 175-180.
- Tansley, A.G. 1939. The British Islands and their Vegetation. Cambridge University Press, Cambridge.
- Webb, D.A. 1985. What are the criteria for presuming native status? Watsonia 15, 231-236.
Tags: Sand dunes
Eryngium campestre
Wed, 08/11/2010 - 11:06 | markd
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Eryngium campestre (L.), Field Eryngo, is distinctive member of the Apiaceae and is an uncontroversial taxon. It has local names of Daneweed, Watling Street Thistle, Hundred Headed Thistle and, in Wales, Ysgallen Ganpen. It is one of five species of Eryngo which are known to occur in Britain (Stace 1997). There are no known synonyms for this species or information on hybridisation.
2n =14.
It is a rigid, pale green,glabrous, branched perennial that grows up to 75cm high and has distinctive spiny leaves and ovoid umbels. It is superficially similar to E. maritimum and the two can occur together e.g. in sand dune habitats but the latter species is often smaller with a blue capitulum rather than green in E. campestre.
It is native to Spain, France, Germany and Greece and other scattered localities in Europe, and is also found in Africa and Asia.
In Britain there are sites in Cornwall, Devon, Somerset and Kent, and it has been recorded as far north as Northumberland, in Wales and in Southern Ireland (Preston et al. 2002).
Click on the map to view full-size on the BSBI Maps Scheme website.
In Britain E. campestre is currently considered to be an archaeophyte (Preston et al. 2002) but it has been thought to be possibly native in Kent and Devon (Stace 1997). It was first recorded in 1662 by John Ray in Devon.
It is a rare plant in Britain being recorded in just twelve 10km squares in the period 1987-99 (Preston et al. 2002) and is listed in the British Red Data Book as Critically Endangered (Cheffings & Farrell 2005), but with the comment ‘cannot distinguish between casuals and established sites.’
In Europe it is often common and locally abundant and sometimes considered an agricultural weed (Salva and Bermejo 1987).
E. campestre is a plant of dry, open grassland but also disturbed habitats such as waste places and roadsides and often shows a preference for calcareous soils (Stace 1997). The sites in Devon include semi-improved and improved grassland on acidic soils as well as disturbed areas (Ingram 2007).
It is not mentioned as a component of any grassland or other open habitat National Vegetation Community (Rodwell 1991-2000) nor in earlier works on vegetation communities (e.g. Tansley 1939).
It is a hemicryptophyte perennial and is insect pollinated, but has also been noted to reproduce vegetatively (Ingram 2007). It flowers from July to September.
Whether this species should be considered native in Britain or not is open to question.
Studies of its genetics in relation to populations on the continent might help to determine the origin of the plant in Britain.
In Southern Europe there are known parasitoids of E. campsetre (Kaydan et al. 2006) which, if also found in Britain, might help to confirm native status (Preston 1986). It would also be useful to know if it occurs in any semi-natural vegetation communities.
Ingram, M. 2007. The Management of Eryngium campestre at Scabbacombe, South Devon. National Trust.
Kaydan, M.B., Kilincer, N., Uygun, N., Japoshvilli, G. & Gaiman, S. 2006. Parasitoids and Predators of Pseudococcidae (Hemiptera: Coccoidea) in Ankara, Turkey. Phytoparasitica 34, 331-337.
Preston, C.D. 1986. An additional criteria for assessing native status. Watsonia 16, p83.
Salva, A.P. and Bermejo, J.E.H. 1987. Floristic composition and agricultural importance of weeds in Southern Spain. Weed Research 28, 175-180.
Tansley, A.G. 1939. The British Islands and their Vegetation. Cambridge University Press, Cambridge.
Webb, D.A. 1985. What are the criteria for presuming native status? Watsonia 15, 231-236.
Tags: Sand dunes