MARMOREUM

Synonym S. schlehanii (Schott). The name S. marmoreum (Griseb.) supersedes S. schlehanii (Schott) on the grounds of priority, this conclusion being made after examination of material from the original locality. (Turril. Bull. Bulg. Bot. Soc. 7: page 124 (1936)). Grisebach’s  description of this species is in Spicil. Fl. Rumel. 1: page 329 (1843), this is 10 years before the name S. schlehanii (Schott) was given to this species.

In nature S. marmoreum is found with a wide-spread distribution in the Balkans and eastern Europe. It is represented by a wide range of polymorphic forms as to shape, size and colouration, much resembling S. tectorum (L.). This species can well be described as the S. tectorum of the Balkans with very similar general range of variation, but with the juvenile leaves at least hairy to some extent and in all its forms tends to be a neater plant.

Description of the typical form: Rosettes are approximately 6 cm in diameter, open in habit, green sometimes with a darker apex or woth the leaves flushed with red over face and back. Rosette leaves are obovate-spathulate to oblong, mostly broader in upper part and abruptly mucronate, flat on face and convex on back, glabrous at maturity except for the stout deflexed marginal cilia. Offsets are on thick stolons about 2 cm in lenght. Flower stems are stout; flower-petals are crimson or rose with a distinct white margin (not paler red as in forms of S. tectorum). Quite an easy species to grow , but in the typical form does not increase so rapidly as S. tectorum and also flowers frequently. The selected form from Durmitor form No. 1 is considered to represent the type form of this species.

 

S. marmoreum fr. Durmitor form No. 1.

Particularly colourful rosettes heavily tinted reddish-brown.

 

S. marmoreum fr. Durmitor form No. 2.

Bright green, medium sized rosettes.

 

S. marmoreum fr. Monte Tirone.

This is a particularly interseting plant because it was collected in the year 1935 from Southern Italy by Dr. R. Seligman, far away from this species normal habitat: Ref. Quart. Bull. Alp. Gard. Soc. Vol. 6, page 359, also Vol. 8, page 303. A very distinct plant with compact or sub-compact rosettes up to 5 cm in diameter with leaves having extra strong cilia on margins with a few hairs on back surface of leaves. The apex of the leaves is strongly marked brown-purple. The leaves are rather more pubescent than the type plant and may well place this form with affinity to the species S. italicum (Ricci), Ann. Bot. (Roma) 27 page 7 (1961), a species with leaves densely pubescent on both surfaces. S. italicum really requires further investigation as to whether it is a distinct species.

 

S. marmoreum fr. Sveta Peta.

Large, pale green flattish rosettes.

 

S. marmoreum fr. Okol.

An extreme variant from the type which was found in northern Albania and was diagnosed by Dr. R.S. Wale in 1938 as S. marmoreum (Griseb.). We have always considered this plant as a separate species, although it obviously has affinity to S. marmoreum and may prove only of varietal status. The main distinction is that the leaves are much thicker than the typical form of S. marmoreum and are convex on leaf face instead of flat. Rosettes are sub-globular, deep green with a pubescence on back of leaves even on matured rosettes and cilia of irregular lenght on margins included to a lesser extent on the back surfaces of leaves.

 

S. marmoreum var. dinaricum (Becker).

This is a distinct varietal form, which derives its name from the Dinaric Alps, Yugoslavia. It is characterized by having small rosettes about 1 to 2,5 cm in diameter with acuminate leaves and smaller flower heads with narrow petals. The rosette leaves are heavily marked dark red-brown near the apex: very attractive.

 

S. marmoreum var. dinaricum (Becker) fr. Karawanken.

A form much the same as above, but with light red-brown colouring on leaf apices.

 

S. marmoreum ‘Brunneifolium’.

A compact growing form with rosettes of a uniform brown colour, turning red in winter; mature rosette leaves glabrous. We assume that this plant was first found growing in nature and is not of garden origin, as Preager does state that Dr. Degen sent him a plant from Trikule near Svinitza in southern Hungary.

 

S. marmoreum ‘Brunneifolium’ (Dark form).

This plant is re-named as only one clone is permissible to occupy a single ‘Cultivar Name’. The new name for this form is Sempervivum marmoreum ‘Chocolate’.

 A very fine plant having slightly less compact rosettes than ‘Brunneifolium’ with dark chocolate coloured rosettes. Mr. Hugh Miller verbally mentioned that he received this form from Preager under S. marmoreum f. brunneifolium no. 2.

 

S. marmoreum ’Rubrifolium’.

This form is also found in gardens under the name S. rubicundum HORT. The origin is obscure, as so far, no native station has been found for it, therefore, we assume that it must be of garden origin. It is a very handsome form with deep red leaves except for the tips and margins which are green.

 

S. marmoreum ‘Ornatum’.

This plant has handsome, large ruby-red rosettes with apple green tips. Unfortunately this rich colouring is inclined to be of short seasonal duration – Mai to August.

This is the S. ornatum of Selwyn Duruz in Gardening Illustrated 52, 325 (1930); not of Correvon in Joubarbes (1924). The origin of this plant is not known, but very unlikely to have been found in nature; suggested parentage is S. marmoreum ‘Rubrifolium’ x S. tectorum var. tectorum. 

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