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Sempervivum species  

06 Oct 2005

This page: Introduction - Index - Species list - Interspecific hybrids
 

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Sempervivum arachnoideum  Sempervivum flower buds  Sempervium flower  Sempervivum seed head

The genus Sempervivum is generally considered to contain about 50 species but the nomenclature is not clearly defined. There are a large number of species described in the literature and an even greater number of names applied to plants in cultivation.

Most species show a wide range of variation especially under different cultivation conditions and many species will freely hybridise. In the past it has been very easy to consider a collected clone to be sufficiently different from others to warrant a separate name. Consequently, many so called species, are probably just variations of a single species or hybrids between species, or even just a variant individual.

It is often very difficult to identify an individual plant, especially when out of it's natural habitat, and many plants offered for sale are incorrectly named and of dubious origin. For the botanist, this makes the group interesting but it can be frustrating for the enthusiast who wants to build up an accurately named collection. In our collection we keep each variety with the name under which we received it unless we are certain that the identification is incorrect. The most desirable specimens are those which are correctly identified and from a named location with field collection data.

The species in the following section are those listed by Radovan Konop (1987). The name of each species is followed by the naming authority, the country or place of origin and, where possible, a brief description of the appearance of plants in cultivation. As a guide to the average size of rosettes the following scale has been used:

very small - 1cm or less
small - 1cm to 3cm
medium - 3cm to 6cm
large - 6cm to 10cm
very large - 10cm or more.

The symbol [P] after a name links to a photograph of that plant in our collection. Go to the Gallery to view small versions of all pictures.

 

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Alphabetical index

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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Sempervivum species list

 

Index ^

S. altum Turrill (1936) [P] - Caucasus Mts. - Medium size, pale green succulent leaves with reddish tips. Red flowers. Offsets are produced on long stolons.

(S. andreanum Wale (1941) - see S. tectorum var. andreanum)

S. annae Gurgenidze (1969) - Caucasus Mts - Red flowers

S. arachnoideum L. (1753) - European Mts. - The familiar cobweb houseleek. Leaf tips are connected by a white cobweb of hairs. There are many varieties which differ in colour, size and degree of cobweb. Red flowers. [Poem]

S. arachnoideum var. bryoides - Very small moss-like rosettes. This is probably better considered as a small growing form of S. arachnoideum rather than a true botanical variety.

S. arachnoideum var. tomentosum - Similar to the type plant but typically has larger rosettes with a more dense cobweb. Some clones develop reddish outer leaves in the summer.

S. arachnoideum 'Album' [P] - An interesting variety which has pure white flowers. The rosette leaves are very pale green.

S. arachnoideum 'Cristate' [P] - The cristate form is rather slow growing but relatively stable.

S. arachnoideum 'Hookeri' [P] - Very small, narrow leafed rosettes which soon grow into dense, moss-like cushions.

S. armenum Boiss. & Huet. (1856) - Turkey - Medium size, dull green leaves with dark tips. Rather slow growing. Yellow flowers.

S. atlanticum Ball (1878) - Morocco - Medium size, pale green colour flushed with red in the summer. Benefits from some winter protection. Red flowers. This is the only African houseleek.

S. atlanticum from Ouikameden [P] - Pale green rosettes with almost a 'waxy' appearance.

S. atlanticum 'Edward Balls' [P] - Globular rosettes which flush with brownish red in the summer. This is a named cultivar but it was probably collected in the wild.

Index ^

S. balcanicum Stoyanoff (1951) - Bulgaria - Medium size, succulent leaves, green and orange-red with darker tips. Red flowers. A member of the S. marmoreum complex.

S. ballsii Wale (1940) [P] - Northern Greece and Southern Albania - Small rosettes of upright smooth green leaves, flushed with pink in the summer. Short stout stolons. Red flowers. The type form was collected from Tschumba Petzi but other geographical varieties are in cultivation.

S. borissovae Wale (1942) [P] - Caucasus Mts. - Small rosettes, bright green leaves with dark brown tips and silver cilia. Red flowers. An attractive species producing large numbers of offsets.

S. brevipilum Muirhead (1969) - Turkey - Medium size, semi-open rosettes. Yellow flowers.

Index ^

S. calcareum Jordan (1849) - French SW Alps - Large, grey-green or bluish-green rosettes, leaves usually distinctly tipped with reddish brown. Petals shade from cream to pale red at the base. There are a large number of different regional varieties and cultivars of this species, many of which are very attractive.

Geographical varieties found in cultivation include clones collected from Alps France, Céüse, Col Bayard, La Colle St Michel, Gleize, Gorges sup. du Cians, Guillaumes [P], Mont Ventoux [P], Route d'Annot and Triora.

S. calcareum 'Extra' [P] - A very striking clone which has large, symmetrical, many leaved rosettes. The leaves are bluish-green with very distinct dark brownish-red tips.

S. calcareum 'Greenii' - A smaller growing variety which produces many offsets.

S. calcareum 'Monstrosum' [P] - A congested variety with unusual cylindrical leaves.

S. calcareum 'Sir William Lawrence' - A large and vigorous cultivar, leaf tips conspicuously tipped with dark reddish brown. Very similar to some of the wild growing plants.

S. calcareum 'Pink Pearl' - Rather elongated leaves with a pinkish tinge in the summer .

S. cantabricum Huber (1934) [P] - North and Central Spain - Deep green pubescent leaves often with dark brown tips. Red flowers. A very attractive species with many geographical forms. Some types tend to die back in the winter but they usually recover in the spring.

S. cantabricum subsp. cantabricum - Northern Spain - Clones in cultivation include those collected from Lago de Enol, Lietariegos, Piedrafita, Riaño, Puerto de San Glorio, Puerto de Somiedo and Vegarada.

S. cantabricum subsp. guadarramense - M.C. Smith (1981) - Central Spain - Clones from Pico del Lobo and Navafria.

S. cantabricum subsp. urbionense - Spain - Medium sized globular rosettes, offsets on short thick stolons. (Sometimes seen named as S. vicentei.) Clones from Picos de Urbion and Valvanera.

S. caucasicum Rupr. (1969) - Caucasus Mts. - Small to medium size open rosettes. Leaves develop a dark red-brown colour in the spring but remain attractive throught the year. Red flowers.

S. charadzeae Gurgenidze (1969) [P]- Caucasus Mts. - Very large rosettes of wide yellowish-green leaves with small dark tips. Pale rose coloured flowers. Offsets are produced on very long stolons.

S. ciliosum Craib. (1914) - Bulgaria, Macedonica, Albania - A very attractive species. Leaves with long marginal cilia. Small symmetrical rosettes and yellow flowers. Slightly sensitive to winter damp.

S. ciliosum var. borisii [P] [P] Bulgaria - A densely hairy variety, silvery grey colour.

S. ciliosum var. galicicum from Mali Hat, Albania [P] - A very neat variety with globular rosettes looking almost like a small cactus. The outer leaves go plum red in the summer.

Index ^

S. davisii Muirhead (1969) - Turkey - Hairy, pale green upright leaves with a small dark tip. Yellow flowers. Rather difficult to keep through the winter.

S. dolomiticum Facchini (1855) - South-Eastern Alps - Small size, dark green rosettes with narrow pointed upright leaves. Red flowers.

S. dominii Konop & Konopova (1984) - Caucasus Mts - Red flowers.

S. dzhavachischvilii Gurgenidze (1969) - Caucasus Mts - Small greyish-green, succulent, upright leaves with a neat dark tip. Red flowers. Tends to grow in tight clusters of rosettes.

Index ^

S. ermanicum Gurgenidze (1969) - Caucasus Mts - Red flowers.

S. erythraeum Velenovsky (1898) - Bulgaria - A beautiful species with velvety grey-green leaves often tinged pink. Red flowers. Requires protection in the winter. A member of the S. marmoreum complex.

S. erythraeum from Pirin Mts - Small pale green, pointed leaves, rather difficult to grow well.

Index ^

S. furseorum Muirhead (1969) - Turkey - Yellow flowers.

Index ^

S. gillianii Muirhead (1969) - Turkey - Yellow flowers.

S. giuseppii Wale (1941) [P] - Northern Spain - Short pale green leaves, densely covered with short white hairs. Red flowers. Produces many offsets on short stolons. Clones collected from Peña Espigüete and Peña Prieta are available.

S. glabrifolium Borissova (1939) - Turkey - Yellow flowers.

S. grandiflorum Haworth (1821) - NW Italy - Large dull green leaves which feel sticky to the touch. Strong resinous odour and large attractive yellow flowers.

S. grandiflorum 'Fasciatum' - An interesting and unusual cristate variety which seems quite stable.

Index ^

S. ingwersenii Wale (1942) - Caucasus Mts - Small to medium size, open rosettes with few succulent dull green leaves, long stolons. Red flowers.

S. iranicum Born. & Gauba (1940) - Northern Iran - Red flowers.

S. ispartae Muirhead (1969) - Turkey - Yellow flowers.

S. italicum Ricci (1961) - Central Italy - Medium size rosettes of erect, bright green leaves with darker tips, hairy all over. Red flowers.

Index ^

S. jakucsii Penzes (1965) - Albania - Probably just another name for S. ciliosum var. galicicum.

(S. juvanii Strgar (1971) - see S. wulfenii subsp. juvanii)

Index ^

S. kindingeri Adamovic (1904) - Yugoslavia - A beautiful species with pale green, densely hairy leaves and short stout stolons. Yellow flowers. A western member of the S. zeleborii complex.

S. kosaninii Praeger (1930) - Yugoslavia - Medium size, dark green velvety leaves. Red flowers. Produces many offsets on long stolons.

S. kosaninii from Koprivnik - A smaller, neater variety.

Index ^

S. leucanthum Pancic (1883) - Bulgaria - Medium size with green, pubescent leaves and yellow flowers. Difficult to keep through the winter.

Index ^

S. macedonicum Praeger (1930) - Yugoslavia - Small rosettes with narrow, tapering leaves, dull green flushed with pink. Red flowers.

S. marmoreum Griseb. (1843) - Balkans - A very variable species with a number of distinct varieties. Clones are available from Monte Tirone (more likely to be a form of S. tectorum) and Okol.

S. marmoreum var. dinaricum (Beck) Soó - Dinaric Alps - Neat rosettes of green leaves with brown tips.

S. marmoreum 'Brunneifolium' - Medium size, pinkish-brown leaves and short thick stolons.

S. matricum Letz (1998) - Northern Hungaria and Southern Slovakia - Hairy leaves. Red Flowers.

S. minus Turrill (1940) - Turkey - Small olive green rosettes, flushed with red in the summer. Yellow flowers. Needs winter protection.

S. montanum Linn. (1753) - European Mts - Usually small but a very variable species, often with a distinct resinous odour. Red flowers.

S. montanum var. burnatii - SW Alps, Corsica - Larger variety with wider leaves.

S. montanum var. carpathicum 'Cmiral's Yellow' - A beautiful bright yellow in the spring and summer, leaves of the flowering rosettes are flushed with bright red. A striking plant but rather difficult to grow well. (Also listed, with photo, in cultivars section)

S. montanum subsp. stiriacum - Eastern Alps - Narrow leaves with brown tips.

S. montanum subsp. stiriacum 'Lloyd Praeger' - A more striking variety, larger rosettes and leaves more heavily tipped with brown.

Index ^

S. nevadense Wale (1941) - Southern Spain - Medium size globular clustering rosettes with short, galbrous or hairy, reddish brown tipped leaves. Red flowers.

(S. nevadense var. hirtellum) - Probably just a slightly hairy form of S nevadense rather than a true botanical variety.

Index ^

S. octopodes Turrill (1937) - Yugoslavia - Small, hairy rosettes with densely packed and very symmetrically arranged leaves. Flowers yellow. The 'type' variety is rare in cultivation and difficult to keep.

(S. octopodes var. apetalum[P]- This clone, whose flowers lack petals, is slightly larger, produces numerous offsets on very long stolons and is easy to grow. An individual monstrose variation rather than a true botanical variety.

S. ossetiense Wale (1942) - Caucasus Mts. - Very succulent, pale green leaves with small dark tips. Flat, open rosettes. Red flowers.

Index ^

S. pisidicum Pesman & Guner (1978) - Turkey - Yellow flowers.

S. pittonii Schott (1854) - Austria - A very attractive species with small hairy leaves. Yellow flowers. Each leaf has a brown apical spot. Produces a large number of offsets which cluster around the main plant but rather sensitive to winter damp.

S. pumilum Bieb. (1808) - Caucasus Mts. - Small globular rosettes with keeled, pointed leaves and silver cilia. Red flowers. The species is quite variable and distinctly different clones in cultivation include those from Adyl Su [P], Armchi, Elbrus and Techensis.

Index ^

S. reginae-amaliae Heldr. (1901) - Greece and Albania - Medium size, dense leafed, open rosettes. Red flowers. Clones in cultivation include those from Kambeecho, Mavri Petri, Peristeria, Sarpun [P] and Vardusa.

S. ruthenicum (1855) Schnit. - Romania - medium to large rosettes of upright, pale green leaves, outer leaves red-brown. Yellow flowers.

Index ^

S. sosnowskyi Ter-Chatsch. (1947) - Armenia - medium size rosettes of wide, succulent leaves, pale green with dark tips.

S. staintonii Muirhead (1969) - Turkey - Yellow flowers.

Index ^

S. tectorum L. (1753) - European Mts. - This is the common houseleek seen in many gardens and often found growing on walls and old roof-tops. There are a number of geographical forms, and many garden cultivars probably have S. tectorum as one of their ancestors. Red flowers.

(S. tectorum var. alpinum) - A name commonly used in horticulture for small growing forms of S. tectorum.

S. tectorum var. boutignyanum (Billot & Gren.) Rouy & Camus - Pyrenees - A small, compact form with rather succulent leaves.

S. tectorum var. andreanum (Wale) Bol. & Vig. [P] - NE Spain - Medium size, upright dull green leaves. This is a compact form of S. tectorum and sometimes named as a separate species.

S. tectorum var. glaucum (Tenore) Praeger - Alps - Dull greyish green leaves.

S. thompsonianum Wale (1940) - Yugoslavia - Small, neat, many leafed rosettes, producing offsets on long stolons. Buff coloured flowers. Possibly a natural hybrid between S. macedonicum and (S. octopodes or S. ciliosum).

S. transcaucasicum Muirhead (1965) - Georgia - Medium size, pale green, pubescent leaves, flushed with pink. Yellow flowers.

Index ^

(S. vicentei Pau (1906) - see S. cantabricum subsp. urbionense)

Index ^

S. wulfenii [P] Hoppe (1831) - Austrian and Swiss Alps - medium to large pale green rosettes with wide, upright, pointed leaves, produces few offsets so slow to propagate.

S. wulfenii subsp. juvanii (Strgar) Fav. & Parn. - Slovenia - Hairy leaves. Yellow flowers.

Index ^

S. zelebori (1857) Schott - Bulgaria - attractive, velvety leaves, pale grey-green open rosettes and yellow flowers. Rather slow growing and difficult to keep.

 

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Interspecific hybrids

  Sempervivum species interbreed relatively easily and produce offspring that often show characteristics intermediate between the parents. Some of the better known hybrids have been given names while others are just known by the names of the probable parent species.

S. christii Wolf (grandiflorum montanum) - Deep green, pubescent leaves with dark tips, pinkish-yellow flowers.

S. fauconnetii Reuter (arachnoideum tectorum) - Jura - Medium size, grey-green, hairy leaves. Red flowers.

S. fauconnetii 'Thompsonii' - Hairy rosettes with a brownish-red tinge.

S. funckii Braun (? arachnoideum montanum tectorum) - Bright green, tightly packed leaves. Red flowers. This plant is well known in cultivation but its true botanical status is not certain.

S. praegeri Rowley - (? ciliosum erythraeum) - Medium size, grey-green, densely hairy leaves.

S. roseum Huter (arachnoideum wulfenii) - Small, clustering rosettes, heavily tinged with red-brown. Red flowers. A vigorous grower which soon forms an attractive clump of rosettes.

S. vaccarii Vaccari (arachnoideum grandiflorum) - NW Italy - Medium size, open rosettes, slightly hairy. Pinkish flowers.

S. widderi Lehm. & Schnittsp (tectorum wulfenii) - Central and Eastern Alps - Medium sized, dull green rosettes. Rare in the wild.

S. arachnoideum calcareum [P] - very attractive, large rosettes of pale green, hairy leaves with dark tips. Pink flowers. Very rare in the wild. The cultivated forms of this hybrid are probably of garden origin.

S. arachnoideum nevadense - green leaves flushed with orange-red, tufts of hairs at leaf tips. Red flowers. A hybrid of garden origin.

S. arachnoideum pittonii - globular, clustering, hairy rosettes, greyish green. Another hybrid of garden origin.

S. cantabricum montanum var. stiriacum 'Lloyd Praeger' [P] - large, pale green leaves, heavily tipped with dark brown. a very striking hybrid of garden origin. Very distinct globular offsets.

S. ciliosum marmoreum - attractive, hairy rosettes which are intermediate between the parents.

S. dolomiticum montanum - small, neat rosettes, green flushed with pink. Very difficult to distinguish from S. dolomiticum without field data.

S. grandiflorum ciliosum - similar to S. grandiflorum but smaller and with hairier leaves. A hybrid of garden origin.

S. pumilum ingwersenii - medium size rosettes which produce large numbers of offsets. In sunny conditions the rosettes are a dark red colour. Probably of garden origin.

 

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