Small evergreen shrub of the Ranunculaceae family, 'Joe' belongs to the Forsteri group, hybrids derived from New Zealand species. It was obtained by H & M Taylor in the United Kingdom, selected in 1983 and introduced in 1985. Its parentage is Clematis marmoraria (s) x paniculata. Its name pays tribute to Joe Cartman, the New Zealand nurseryman who sent the seeds to the breeders.
Unlike the dwarf cultivars of the group, 'Joe' is a vigorous and climbing plant, reaching 1.5 to 2 meters in height. The evergreen foliage is finely cut, dark green and shiny.
The white flowers are produced in abundant panicles in April. The tepals number five to eight, obovate, slightly recurved with age, downy on the outer surface, with a diameter of 2 to 5 cm. The anthers are beige to white on yellow filaments.
It requires a sunny exposure, well-drained soil, and winter protection in regions with severe frosts. It is mentioned as ideally suited to cultivation under cold shelter or in a conservatory.