View source for Lower Bostraze and Leswidden SSSI

{{Short description|Biological Site of Special Scientific Interest in Cornwall, England}}
{{Use dmy dates|date=April 2022}}
{{Infobox SSSI
|name= Lower Bostraze and Leswidden
|image= Stream at Lower Bostraze - geograph.org.uk - 88490.jpg
|image_caption= A stream at Lower Bostraze 
|aos= Cornwall
|interest= Biological
|gridref={{gbmappingsmall|SW385315}}
|coordinates = {{coord|50.1262|-5.6608|type:landmark_region:GB|display=inline,title}}
|displaymap= United Kingdom Cornwall (mainland)#UK England
|area={{convert|2.3|ha|km2 sqmi|sigfig=3}}
|notifydate={{Start date|1996}}
|enref=2000182
}}

'''Lower Bostraze And Leswidden SSSI''' is a [[biological Site of Special Scientific Interest]], located on the [[Penwith Peninsula]], [[Cornwall]], England, a little to the east of [[St Just in Penwith|St Just]], approximately 8 km west of [[Penzance]].

==Geography==
There are two discrete parts of this site – '''Lower Bostraze China Clay Works''' and '''Leswidden Block Works'''; together they are 23,000 m<sup>2</sup> in size. Lower Bostraze is located at {{gbmapping|SW385315}}, and Leswidden at {{gbmapping|SW390310}}. The site was [[SSSI notification|notified]] as an SSSI in 1996. The site lies within the Cornwall Area of Outstanding Natural Beauty and the Penwith Heritage Coast and is partly within the West Penwith Environmentally Sensitive Area.<ref name=SSSI>{{cite web|title=Lower Bostraze And Leswidden|url=http://www.sssi.naturalengland.org.uk/citation/citation_photo/2000182.pdf|archive-url=https://web.archive.org/web/20121024220421/http://www.sssi.naturalengland.org.uk/citation/citation_photo/2000182.pdf|url-status=dead|archive-date=24 October 2012|publisher=[[Natural England]]|accessdate=27 October 2011|year=1996}} </ref> The site has also been designated a [[Special Area of Conservation]].<ref>{{cite web|title=Lower Bostraze and Leswidden|url=http://jncc.defra.gov.uk/protectedsites/sacselection/sac.asp?EUcode=UK0030064|publisher=[[Joint Nature Conservation Committee]]|accessdate=12 January 2012}}</ref>

Both parts of the site are underlain by the Land's End [[granite]], part of the [[Cornubian batholith]]. Zones within the granite, altered by kaolinisation, have been extensively worked for [[china clay]] until recent years. China clay was discovered in the Balleswidden sett in 1880 and both areas are located within disused china clay workings, consisting of pits, benches, spoil tips and granitic debris with sparse vegetation cover.<ref name=SSSI /><ref>{{cite news|title=Mining in St Just|work=The Cornishman|issue=98|date=27 May 1880|page=8}}</ref>

==Wildlife and ecology==
The site's SSSI status is due to the presence of important populations of a very rare liverwort, the [[Western Rustwort]] (''Marsupella profunda''). This species is rare in a British context (it is known from only two other locations in the [[United Kingdom|UK]]: [[St Austell Clay Pits]] and [[Tregonning Hill]], both within Cornwall).<ref name=StAustell>{{cite web|title=St Austell Clay Pits|url=http://www.sssi.naturalengland.org.uk/citation/citation_photo/2000425.pdf|publisher=[[Natural England]]|accessdate=11 January 2012|year=2000}}</ref> However, it is also internationally rare, being known only from [[Portugal]], the [[Canary Islands]], the [[Azores]] and [[Madeira]]; throughout this range it is a rare species. At Lower Bostraze and Leswidden, Western Rustwort is generally found growing on micaceous or clay waste substrates which are flat or gently sloping. Some patches occur on granitic rocks, usually where these are soft or crumbling. It appears to be a [[pioneer species]], the largest populations being found on surfaces showing the early stages of [[colonisation (biology)|colonisation]] by other [[bryophyte]]s and by [[vascular plant]]s.<ref name=SSSI />

The conservation charity [[Plantlife]] designated the St Just Moors, part of this SSSI, an [[Important Plant Area]] for the occurrence of Western Rustwort and the [[green algae]] [[desmids]].<ref>{{cite web|title=St Just Moors (Lower Bostraze & Leswidden)|url=http://www.plantlife.org.uk/wild_plants/important_plant_areas/st_just_moors_lower_bostraze_leswidden/?cat=10|publisher=[[Plantlife]]|accessdate=17 November 2011|archive-url=https://web.archive.org/web/20120607171013/http://www.plantlife.org.uk/wild_plants/important_plant_areas/st_just_moors_lower_bostraze_leswidden/?cat=10|archive-date=7 June 2012|url-status=dead}}</ref>

==History==
The [[Kaolinite|china clay]] works at Leswidden started in 1886 or 1887 and were suspended in April, 1887 due to problems with water supply.<ref>{{cite news |title=St Just |work=The Cornishman |issue=458 |date=21 April 1887 |page=5}}</ref>

==Toponymy==
The meaning of Bostraze is "dwelling in a flat-bottomed valley". There is a place called Bostrase in the parish of St Hilary (with the same meaning). The meaning of Leswidden is "white / fair ruin".<ref>[[Craig Weatherhill]] (2009) ''A Concise Dictionary of Cornish Place-Names''. Westport, Co. Mayo: Evertype {{ISBN|978-1-904808-22-0}}; pp. 24 & 46</ref>

==References==
{{Portal|Cornwall}}
{{Reflist}}

{{SSSIs Cornwall biological|state=collapsed}}

[[Category:Penwith]]
[[Category:Sites of Special Scientific Interest in Cornwall]]
[[Category:Sites of Special Scientific Interest notified in 1996]]
[[Category:Special Areas of Conservation in Cornwall]]