Cerastium holosteoides

I’ve just been reading that what I had thought of as Cerastium fontanum is actually Cerastium holosteoides and that C. fontanum is an alpine species.
I just have an old copy of Stace which separates the subspecies and holosteoides there is not the species I see commonly. It is described as having leaves with few hairs above.
I can’t find any recent information on this change.
Can anyone direct me to a paper or article about this?

Can you point me at the text, or if it’s not online offer a quote?

The 3rd edition of Stace recognises subsp. scoticum, subsp. vulgare and subsp. holosteioides, and gives Cerastium holosteioides as a synonym of the last. Subsp. scoticum is a narrow endemic (Stace says Angus, Sell & Murrell a specific hill - they say in Forfar but referring to BSBI Maps and StreetMap.co.uk it’s in Angus).

Sell and Murrell reject subsp. holosteiodes, and split subsp. vulgare into 4 varieties. var. glandulosum in Britain is restricted to west Sutherland and south Kintyre - these plants had previously been placed in subsp. scoticum. Stace describes them as large-flowered var. vulgare. var. lucens corresponds to Stace’s subsp. holosteioides; (in Britain?) it is restricted to the banks of the Tay and the Newcastle Tyne. Sell & Murrell give Cerastium holosteioides auct. as a synonym, indicating that they do not consider it the true Cerastium holosteioides. The other two varieties are var. serpentini and var. vulgare. Sell & Murrell say that var. serpentini is found on serpentine, in coastal rocks and on mountains, but don’t give an indication of how widespread it is. var. vulgare is the widespread form. var. serpentini is described as smaller than var. vulgare, with petals consistently (rather than sometimes) a little longer than the sepals, and with a narrower range of seed size. Unless the small, compact, mural form of Cerastium fontanum is var. serpentini, I don’t see a reliable way of distinguishing them, except that the larger, lax, grassland morph is definitely var. vulgare.

subsp. fontanum is an alpine taxon not found in Britain.

The common British plants don’t fit the descriptions of subsp. holosteioides/var. lucens. A possible explanation for what you’ve read is that someone has chopped the subspecies and varieties up differently, so I looked at Euro+Med Plantbase and POWO. Euro+Med have a subsp. lucorum, not found in Britain. POWO have this, and also subsp. grandiflorum and subsp. membranaceum. Euro+Med doesn’t recognise Cerastium holosteioides (but does have a Cerastium holosteum, from eastern Transcaucasia, not recognised by POWO). POWO does, and gives Cerastium vulgare (the basionym for subsp. vulgare) as a synonym, confirming the hypothesis that someone has split the subspecies differently. subsp. scoticum remains in Cerastium fontanum. I’ve tracked backwards from POWO to a Greek checklist, but that offers no discussion and no obvious relevant references, but I’ve tracked the original transfer using the cited authority - to Buttler (1997). Cut and paste of the text into Google Translate isn’t working, and I haven’t got the time to type the relevant text in just now, but it seems that he chopped Cerastium fontanum into 3, and subsp. vulgare went with holosteioides.

Tracking back one more paper, it seems that Buttler was following Moschl (1973) (but Moschl used the name triviale rather than vulgare for the taxon under issue). Moschl goes into somewhat more detail.

a little here
Cerastium fontanum vs. Cerastium holosteoides · iNaturalist.
Less here Irish Wildflowers - Common Mouse-ear, Cerastium fontanum subsp holosteoides
Pretty confused here Cerastium | Species Dictionary | UK and Ireland | iSpot Nature
but note the UKSI entry of Cerastium alpinum x fontanum = C. x symei Cerastium ×symei Druce
My Stace is old too!
LvtG came while I was musung…

I have always been confused about this and could often not get plants to match characters properly. I thought it was just me!

It seems to me that all that has been done is change the rank and name of the common British taxon - under this concept Cerastium fontanum is in Britain restricted to Meikle Kilrannock in Angus. But at lot of recent Floras (and WFO) continue to use the other classification.

Thanks, I’m not much wiser.
It seems that names have been switched based on DNA work, something we are all used to. I’d really like to see a paper which makes it clear.

I’ve seen nothing to suggest DNA data is responsible this time. I haven’t tried a careful translation of the German, but I have the impression that it’s a lumper/splitter issue, with more weight being placed on ecology than on indumentary characters, i.e. separate fontanum s.s. from vulgare because it’s alpine rather than separate holosteoides from vulgare because it’s subglabrous. I’ve edited my post above to make the dates of both papers explicit.
Sell & Murrell say of var. lucens “(it) has been called C. holosteioides Fr., but type material of that plant has glandular hairs on its sepals and pedicels”.
POWO don’t even recognise subspecies within C. holosteioides, in spite of the considerable variation in hairiness.

In Britain you can generally record Cerastium fontanum subsp. vulgare instead of Cerastium fontanum.
Total numbers of records in the BSBI data base are Cerastium fontanum (281023), subsp. vulgare (28061) (only some VC recorders use this name), subsp. holosteoides (3195) and subsp. scoticum (11). Sell & Murrell’s varietal names aren’t used in the BSBI database. Records of subsp. holosteoides are more widespread than the range that Sell & Murrell give for var. lucens, with notable clusters in Orkney, East Yorkshire, south east Wales and Kent.

I’ll stick with that for now.