Trichophorum cespitosum group

[AndyAmphlett]

Hi,

There seems to be confusion over allocation of records on the DDb to taxa within the Trichophorum cespitosum group. Screenshot below.



The majority of records have been allocated to T. cespitosum (L.) Hartm, which is incorrect (this is the apparently rare taxon). All my records for the rare taxon, entered into MapMate as T. cespitosum subsp. cespitosum (via Mapmate Centres 2dd and 4qq), are included under this species. T. cespitosum s.s. includes a mix of correct records (some also entered as T. cespitosum subsp. cespitosum), and presumed errors ( eg vc 3 and vc4). Most of the T. cespitosum (L.) Hartm records should be T. cespitosum s.l., but not all of them.

Hopefully most of this can be corrected at source within the DDb. The confusion is perhaps not surprising given the unfortunate recent change of names within the genus.

Andy.

[qgroom]

Hi Andy,
this is a problem. If Tom is able to reassign all the records under 'T. cespitosum (L.) Hartm.' to 'T. cespitosum s.l.' we can merge 'T. cespitosum (L.) Hartm' with 'T. cespitosum s.s.' to clean up the names a bit.
Quentin

[AndyAmphlett]

Hi Quentin,

that wouldn't work as there are records for T. cespitosum s.s. within 'T. cespitosum (L.) Hartm.. To illustrate what has gone on with records I have responsibility for (MapMate Centres 2dd and 4qq), I have summarised records for Trichophorum in these copies of MapMate, and how they are held within the DDb.



NB Neither copy of MapMate has been updated to Stace 3 names. It is heartening that there is an exact match between the number of records in MapMate and the DDb. Hybrids are correct in the DDb. T. cespitosum s.s., which in my copies of MapMate are entered as subsp. cespitosum are placed within T. cespitosum (L.) Hartm. in the DDb. This is ok, but there are thousands of other records also under this name which are not this species. All my records for T. cespitosum s.l. (entered as T. cespitosum in MapMate) have been allocated to T. germanicum. This is incorrect, but raises a different question.

I suggest that all records be allocated to T. cespitosum s.l. / agg., unless the source record clearly allocates the record to one of the individual species or hybrid, and that that is believable. Records for T. cespitosum prior to Swan's paper in Watsonia, except those determined by him, should be allocated to the agg. taxon. I don't know what options there are for data entry in the most up to date MapMate species dictionary, but if it lacks an option for entering records as the agg. taxon, then confusion may continue.

The problem here is clearly the direct result of a nomenclatural change (latest sedges handbook and Stace 3), that serves taxonomists, but not the users of names. Hopefully existing records can all be sorted out, but there will probably be a need to check all new records for Trichophorum as they are added to the DDb.

Andy.

[qgroom]

In that case, we could merge 'T. cespitosum (L.) Hartm' with 'T. cespitosum s.s.' before we start cleaning up the mess. I'm keen to get rid of this unnecessary taxon.

I think a date based movement of records from 'T. cespitosum (L.) Hartm' to 'T. cespitosum s.l.' would work, there are also a large number of VCs where 'T. cespitosum (L.) Hartm' has never been recorded and these could be moved too. The remains would have to be done manually, however, it might be easier to move them all to s.l. and only move the good ones back to 'T. cespitosum (L.) Hartm'.
Quentin

[jimmcintosh]

Just to pick up on that point about how MM with all the latest patches treats the Trichophorum cespitosum group:

There are four options:
Scientific (vernacular)
Trichophorum cespitosum (Northern Deergrass)
Trichophorum cespitosum nothosubsp. foersteri (T. cespitosum subsp. cespitosum x subsp. germanicum)
Trichophorum germanicum (Deergrass)
Trichophorum germanicum agg. (Deergrass)

The point to note here is that it is the Trichophorum germanicum name which takes the agg. suffix.
Jim

[jimmcintosh]

I should have pointed out that folk who updated their MMs with the latest patches, need to be aware that Trichophorum cespitosum is the now the rare Northern Deergrass taxon. (A warning was issued at the time.)

Jim
PS There will be no problem to those who enter data using BRC codes. They haven't changed!