S. altum - name, synonim

Sempervivum altum was first described by Turrill in 1936.

Habitat of this species are Caucasus Mts. - 1500 - 2000 m above se alevel

Description: Medium size (2,5 do 5 cm in dimather), pale green succulent leaves. Offsets are produced on long stolons. Leaves of the rosette are 2 cm long, 8 mm wide and 3 mmm thick with fine hairs on both sides. Leaves are tipped scarlet red. Red flowers of 2,5 - 3 cm in diamether and 12 - 15 cm in high. Stolons are 8 to 21 cm long. This plant needs protection from winter rain.

Synonym for this species is Sempervivum pumilum .

Link to a photo:

http://www.cactofili.org/specie.asp?mode=&gen=sempervivum&sp=altum

Synonim for this specie is Sempervivum pumilum .

Excuse me Renee, but I'm not agree with you

S. pumilum is not a synonym of S. altum. It's a good species.
Please see Sempervivophilia (G. Dumont)

Sorry, I found S. pumilum as a synonim for S. altum here:

http://www.efloras.org/florataxon.aspx?flora_id=120&taxon_id=242442389

I was not aware this is wrong. Can you explain more about this mistake? It might be an unvalid classification ...

Sempervivum altum is very much alike S. annae und S. ossetiense.

It looks like Chromaphyo is right. In book Caucasus and its flowers (Vojtech Holubec, 2006) the author writes about S. pumilum M. Bieb. without any synonyms and also RHS Plant finder states both species.
Last year I also found both mentioned species in Botanical gardens in Belgium:

S. altum



S. pumilum

Subordinated taxa:

Sempervivum altum var. altum

Sempervivum altum var. ossetiense

Antonina Georgievna Borissova (1903–1977), a Russian botanist, put in 1939 S. pumilum as a synonim of S. altum. (Urs Eggli, Sukkulenten - lexikon: Crassulaceae) This was later proven wrong.