S. x fauconnetii - in general

S.x fauconnetii was firste described by Reuter in 1832 and it is a crossing between S.arachnoideum and S.tectorum.

S. fauconnetii includes folowing :
- S.x piliferum (Jordan)
- S.x flavipilum (Hausmann/Rowley)
- S.x rubellum (Timbal-Lagrave)
- S.x pilosellum (Lehmann & Schnittspahn)
- S.x pomelii (Lamotte)
- S.x angustifolium (Kerner)
- S.x heerianum (Brúgger)
- S.x thomayeri (Correvon)
- S.x thompsonii (Lindsay)
- S.x mettenianum (Hausmann)ex Hayek

Hello
In fact, S. x fauconetti is a natural hybrid from Jura's mountain and is present only in two locations in Jura, France.
S. x piliferum is a natural hybrid for the crossing S. tectorum x S. arachnoideum.
S. x pomelii is a natural hybrid for the crossing between S. arvernense x S. arachnoideum tomentosum. He live only in Massif Central, France
According to G. Dumont, S. arvernense is a true species or a subspecies of S. tectorum.

I know you know a lot about French Alps - can you please tell me where the Jura mountain (or mountain range?!) is located. Thank you!

Jura is a area and a Mountain between France and Switzerland. See the map here:



Here live S. tectorum decoloratum and S. x fauconetti.
The hybrid S. x fauconnetii is a crossing between S. tectorum decoloratum x S. arachnoideum. The surprise is that S. arachnoideum don't live in this area ! This species has disappeared from this place.
The hybrid is protected by law and is prohibited from harvesting


S. fauconnetii [in situ / between Grd Mt Rond et Colomby 1500 m, 98B01] from Sempervivophila

In the Massif Central, a volcanic mountain in central France live S. arachnoideum tomentosum, S. arvernense (or S. tectorum arvernense) and S. x pomelii the hybrid between these two species


S. x pomelii and S. arachnoideum tomentosum in Chastel sur Murat FOL 2006/02B (Cantal)


S. x pomelii and S. arachnoideum tomentosum in Rocher de Bonnevie FOL 2006/01C (Cantal)

S. x piliferum is the name for others hybrid between S. arachnoideum x S. tectorum in Alps and in Pyrenees.


S. x piliferum "Thompsonii" a hybrid with uncertain origin

Sorry for my bad english !
Olivier

I've found a description of S. × fauconnetii from Jura that goes like this:

Medium size, grey-green, hairy leaves. Red flowers.

S. x rubellum:

1. is a form of S. x fauconnetti (Reuter, 1832)

2. and a synonym of Sempervivum × fauconnettii nm. rubellum (Timbal-Lagrave) G.D. Rowley (1958)