Schlumbergera Microsphaerica - Taxonomy

Taxonomy

The epithet microsphaerica is derived from the Greek mikros meaning small and sphairikos meaning spherical. The stem segments of the species are shaped like small cylinders or spheres.

Like the taxonomy of the genus (see Schlumbergera: Taxonomy), the taxonomy of Schlumbergera microsphaerica is complicated. The first person to name the species was Schumann in an 1890 paper in which he described three species: Cereus microsphaericus, C. obtusangulus and C. parvulus. However, he seems to have decided afterwards that the three species were not distinct, and in a monograph published later, which included an illustration, used only the name C. obtusangulus, although he did not actually say that the three species were the same. On this basis, some authors used C. obtusangulus as the basionym ("base name") when they later transferred the species to Epiphyllanthus (Berger in 1905), Zygocactus (Löfgren in 1918), Epiphyllum (Lindberg in 1926) and Schlumbergera (David Hunt in 1969). Other authors chose C. microsphaericus as the basionym, since this was the first name in the original paper, when they transferred the species to Epiphyllanthus (Britton & Rose in 1923), Arthrocereus (Berger in 1929) and Schlumbergera (Otto Hövel in 1970).

A further complication is that the original material on which Schumann had originally based his species was lost, so that whether C. microsphaericus and C. obtusangulus were in fact the same species or not cannot now be investigated. In 1991, Taylor formally united the two possible names by designating an illustration of what was at the time called Zygocactus obtusangulus – the right hand drawing in the plate shown in the taxobox – as the neotype of C. microsphaericus (i.e. this illustration became the substitute for the missing specimen on which Schumann had based the name). Under the rules of botanical nomenclature, this means that microsphaericus rather than obtusangulus became the correct specific epithet.

Thus the synonyms of Schlumbergera microsphaerica include:

Epiphyllanthus obtusangulus

Zygocactus obtusangulus

Epiphyllum obtusangulum

Schlumbergera obtusangula

Epiphyllanthus microsphaericus

Arthrocereus microsphaericus