FORSTERIANUM  (Sm.) Grulich, 1984

Synonyms :

Sedum rupestre  L. (1753) in part / Sedum reflexum var. rupestre  (L.) Grenier & Godron nom. incorr. (1848)

Sedum forsterianum  Smith (1802) / Sedum rupestre ssp. forsterianum  (Smith) R.L.Evans (1983) nom. inval. / Petrosedum forsterianum  (Smith) Grulich (1984)

Sedum elegans  Lejeune (1811) / Sedum rupestre ssp. elegans  (Lejeune) Hegi & Em.Schmid (1922) / Petrosedum rupestre ssp. elegans  (Lejeune) Velayos (1989)

Sedum aureum  Wirtgen ex Schultz (1844) / Sedum reflexum var. aureum  (Schultz) H.Jacobsen (1973)

Sedum lejeunianum  Hornung ex W.D.J.Koch (1857)

Sedum trevirense  Rosbach (1857)

Sedum juranum  Gay (1863)

Petrosedum rupestre (L.) P.V.Heath  var. forsterianum (Sm.) Niederle comb. nov. (2014)

Distribution : Western Europe. Type locality: U.K., Wales, Cardiganshire, at the Rhydoll Falls, near the Devil's Bridge.

Description (according to Praeger, Evans and IHSP) :  

Perennials with non-flowering branches procumbent, rooting, with more or less flattened leaves aggregated into terminal loose cone-like rosettes, more or less adnate to the stem at their their bases.

Leaves alternate, glabrous, 10-15mm long, green or glaucous, elliptic in section, acute and mucronate at the tips, and bearing a short spur at their base, most prominent on the bracteoles. Dead leaves persisting.

Inflorescence : Terminal, erect, 20 - 30 cm long, topped with an umbellate cyme of c.5 forked & recurved  branches, drooping & globose when in bud, glabrous throughout. Bracteoles like the leaves, but reducing in size upwards.

Flowers stellate, mostly 5-7 partite, rarely up to 9-merous, on short pedicels. Sepals 2-3 mm long, green, more or less triangular, united at their bases but nearly free, only slightly fleshy, persistent in fruit. Petals free, spreading, oblong-lanceolate, yellow, 6 - 7 mm long. Stamens spreading, of similar length to the petals, yellow, with yellow anthers. Nectar scales yellowish green. Carpels erect, yellowish brown.

Close to and most frequently confused with Petrosedum rupestre (L.) P.V.Heath, which is distinguished in having terete leaves, reflexed at their base, not persisting, and not crowded towards the stem apices; the inflorescence is smaller with only 3-5 branches. P. rupestre has a more east European distribution, but they overlap in France.