This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
A peculiar genus of evergreen shrubs belonging to the Asparagus group. Flowers imperfectly dioecious. Perianth six-parted to the base, persistent. Fruit a berry. Name of uncertain origin. There are several species, some of them remarkable on account of the reduced leaves and flattened branches (cladodes), on whose face or margin the flowers are produced.
1. R.aculeatus. Butcher's Broom. - A dwarf much-branched shrub with small ovate rigid spinescent cladodes bearing the small greenish flowers, which appear in April, and are succeeded by bright red berries about the size of a pea. A native of the South and West of England, etc.
R. androgynus is a climbing plant from the Canaries, with flowers on the edges of the cladodes. R. Hypoglossum, a South European species, has the flowers on the upper side of the cladode with a smaller cladode overhanging them; and R. hypophyllum, also from the South of Europe, with the flowers beneath the cladodes. These three species are rare in gardens, and rather tender.