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Sagina apetala records

Posted: Sun May 27, 2018 11:03 am
by davidbroughton
Would value thoughts on the records of Sagina apetala in the DDB. It is a species I have undoubtedly been overlooking but is it as widespread as records indicate? I guess a more useful query is what happened with the original sens. lat. records when apetala and filicaulis were subsequently raised to species level? Presumably a number of records were of the agg., were these records segregated as a sens. lat. grouping or lumped with apetala sens. str? Looking at VC64 there seem to be a lot of dots which are not supporting by any records I am aware of. There has not been a culture of recording subspecies in local recording groups who have contributed most of the records over recent decades, and this species was treated as sens. lat. in the County Atlas with only a note that 'both subspecies appear to be equally widespread'. The map in the Atlas is suspiciously similar to one generated from the DDB, and the lack of resolution in the underlying records of the latter does not reassure.

Re: Sagina apetala records

Posted: Mon May 28, 2018 12:54 pm
by AndyAmphlett
Most of the potential confusions arising from name changes in Stace 3rd edition are listed in this MapMate Newsletter - http://www.mapmate.co.uk/newsletters/102. But Sagina is not mentioned.

There are a suspiciously high number of records for Sagina apetala for date class 1987 - 1999 cf post 1999, and I suggest that anything recorded as Sagina apetala (without subspecies) before Stace 3 should probably be referred to the s.l. taxon, which is an option available in the DDb. Records could be bulk edited with an explanation as to why the edit was made. From a quick look at vcs I know, it looks looks like the issue is widespread, but VCRs would need to carefully investigate records for their vcs.

As this may be a general problem, it may be best for Tom to deal with it. Kevin Walker mentioned to me a few days ago that he and Tom were identifying 'problem' taxa such as this.

Re: Sagina apetala records

Posted: Tue May 29, 2018 11:56 am
by admin
Thanks for highlighting this issue. I'm meeting with Kevin next week, I'll discuss that with him then.

Re: Sagina apetala records

Posted: Tue May 29, 2018 7:04 pm
by davidbroughton
Thanks for looking at this. I have also been suspicious of the volume of historic records for Rumex acetosella subsp. acteosella? Were that many people really recording this historically or should these be just Rumex acetosella?

Re: Sagina apetala records

Posted: Tue Nov 19, 2019 6:42 pm
by VCR111
I suggest another candidate for the list of 'problem taxa' - Arctium minus. I notice a number of records pre-2000, some Atlas, others earlier, identified as ssp minus for VC111. I am not aware of spp. records from here and suspect the lower taxon level was added later. There are also a few for ssp. pubens which I cannot understand. To compound the problem, Arctium nemorosum was until fairly recently (?) treated as a ssp of A. minus (Sell & Murrell, 2007) and it seems likely, based on those few herbarium specimens that have been re-determined and most recent records from VC111, that the Arctium minus records should be referred to A. nemorosum. This is likely to be so for most if not all records from the north. This might be solved by re-naming all records about which there is uncertainty A. minus s.l. provided the aggregate includes nemorosum.

Re: Sagina apetala records

Posted: Tue Nov 19, 2019 6:43 pm
by VCR111
I suggest another candidate for the list of 'problem taxa' - Arctium minus. I notice a number of records pre-2000, some Atlas, others earlier, identified as ssp minus for VC111. I am not aware of spp. records from here and suspect the lower taxon level was added later. There are also a few for ssp. pubens which I cannot understand. To compound the problem, Arctium nemorosum was until fairly recently (?) treated as a ssp of A. minus (Sell & Murrell, 2007) and it seems likely, based on those few herbarium specimens that have been re-determined and most recent records from VC111, that the Arctium minus records should be referred to A. nemorosum. This is likely to be so for most if not all records from the north. This might be solved by re-naming all records about which there is uncertainty A. minus s.l. provided the aggregate includes nemorosum.