The vascular pattern of the flowers of Sedum anacampseros (Crassulaceae)

The Sedum telephium group ( = Hylotelephium Ohba, Sedum L. subgen. Telephium (S. F. Gray) Clausen,, S. sect. telephium S. F. Gray) is generally considered to be a distinct and natural group. However, its taxonomic position is still rather controversial (Clausen 1975, Ohba 1977, 1978). All species of this group have a short, fleshy caudex and often thickened, tuberous roots, hapaxanth flowering shoots with flat leaves, and a corymbose inflorescence. The flowers have stipitate or attenuate carpels. It is assumed that the species of the S. telephium group are further characterized by flowers with a primitive vascular pattern (l.c.). The flowers of S. sieboldii Sweet ex Hook., S. spectabile Boreau, S. tartarinowii Maxim., S. telephioides Michx. and S. telephium L. (= S. maximum (L.) Hoffm.) have six independent whorls of traces departing from the stele (Wassmer 1955, Quimby 1971). Two species of the S. telephium group, S. telephium and S. anacampseros L. are native to Europe. S. anacampseros is endemic to the mountains of southern Europe. It occurs in the Pyrenees, SW Alps and the Apennines (Webb 1964). Although S. anacampseros resembles the other species of the S. telephium group in gross morphology it differs notably in some aspects of the flower as well as in its hibernating, creeping and rooting, leafy non-flowering shoots (Praeger 1921, Froderstrom. 1930). The carpels of S. anacampseros are strongly stipitate {fig. If-h) and in this respect resemble the other species of the S. telephium group. However, in contrast to the flowers of the five species mentioned above the flowers of S. anacampseros have only four whorls of traces departing from the stele (fig. la-g). The dorsimedian traces of the carpels fuse with the combined traces of the petals and epipetalous stamens, and the lateral traces of the carpels unite with the traces of the episepalous stamens (fig. Id-f). The vascular pattern of the flowers of S. anacampseros agrees with group three of Quimby’s system, which is the most common within the genus Sedum and most probably throughout the Crassulaceae (Quimby 1971).