Crassula rubricaulis, the red-stem crassula or rooistingelplakkie in Afrikaans, is a dense shrublet reaching heights around 30 cm. The specific name, rubricaulis, is a Latin word meaning red-stemmed.
The plant bears large heads of small white flowers. The blooming season is summer, autumn or winter. Such differences are more likely for plants widely distributed, bringing about different growing conditions in parts of the region.
The distribution ranges from the southern Cape around Swellendam and the south of the Little Karoo to the Eastern Cape as far as Uitenhage.
The habitat includes coastal montane fynbos and sandstone outcrops. The western part of this region receives more winter rain, the eastern part summer rain and in parts much less of it. The species is not considered to be threatened in its habitat early in the twenty first century.
It may well be that your garden specimen also displays some different characteristics, due to e.g. the particular microclimate, position and sourcing of your plant (Frandsen, 2017; Smith, et al, 2017; Vlok and Schutte-Vlok, 2015; iNaturalist; http://redlist.sanbi.org).