The rhubarbs include some small alpine species, and some dramatic giants. They all provide unusual and interesting structure, often with good autumn colour.

Rheum alexandrae SDR4757 has tall flower stems, covered in triangular creamy yellow bracts, each the size of a hand. These remain after flowering, and the seeds ripen behind them, out of sight. The leaves are fleshy, many of them arising directly from the crown. Looks great with pale yellow Primula sikkimensis.