Rheum alexandrae is a rare species of rhubarb from the mountains of China and Tibet with heart-shaped leaves and yellow flowers.

Rheum palmatum is an ornamental rhubarb with huge leaves, often flushed with red beneath.

Rheum rhabarbarum 'Glaskin's Perpetual' is a culinary rhubarb with short, tender stalks that are bright red, tender, very sweet and juicy.

Rheum rhabarbarum 'Holsteiner Blut' is a culinary rhubarb known for its great flavour and bright red stalks.

Ornamental rhubarb with large, spade-shaped foliage emerging red-flushed later with green tops and bold red undersides.

Rhipsalis cereuscula is a fascinating, epiphytic cactus with light-green stems that have a striking resemblance to rice grains.

Rhodochiton atrosanguineus 'Purple Bells' is an exotic tender vine with dark purple tubular flowers and light purple calyces.

Rhododendron campanulatum subsp. aeruginosum 'Blue Ox' has foliage emerging powder blue on tight mounds 2 feet tall and wide.

Rhodoendron sinogrande has the largest leaves of any rhododendron which can be three feet long and one foot wide.

Rhododendron 'Boule de Neige" midseason flowers are pure white.

Rhododendron 'Cody' has frilly-edged pink flowers, pale yellow overlaid with moderate purplish pink at edges.

Rhododendron 'Nancy Evans' has orange-red buds open to yellow hose-in-hose blossoms in mid-season.

Rhododendron 'Neon' has a vivid orangey-peach with a yellow throat, dark leaves, and compact growing to boot!

Rhododendron 'Percy Wiseman' has rare peach-colored blossoms that appear in midseason.

Rhododendron 'Polarnacht' has frilly deep dark purple blooms with spotted red throats are held in trusses of 12-14.

Rhododendron 'Purple Passion' has regal, deep reddish purple blooms highlighted with white and delicate maroon spots.