Epimediums grow from a woody or wiry rhizome. These vary in diameter from about 2mm to 7mm or even slightly larger, depending on the species and the strength of the plant. According to species, plants may have short thicker rhizomes giving a dense clumping habit or have thinner spreading rhizomes giving a wider spreading habit. Thin wiry roots for anchorage and the uptake of water and nutrients radiate from the rhizomes. Rhizomes and older roots are generally a light brown colour.
Above ground, the leaves can be deciduous or evergreen, but they are always carried on thin wire like stems which are quite tough when mature. The leaves carried on the wiry petioles are most commonly compound with from two to more than 50 leaflets. There are a small number of species where the leaves, which are not on flowering stems, are simple with just the one blade to the leaf. Many species carry three leaflets. Mature leaves especially on evergreen species are quite tough and leathery, and here in our garden stay looking good over most winters.The Flowers are quite variable in colour and shape. The flower in bud displays four outer sepals. These are generally shed quickly as the flower opens. Inside these are the four inner sepals, which can be quite small or large and showy. There are then four petals which can be simple oval shaped or extended into long spurs. Frequently the inner sepals are of a contrasting colour, for example red inner sepals occur in several species with yellow petals. The complete flowers vary considerably in shape from small hanging cups or bells to pendulous stars to larger cup shape with outer spurs, to flowers provoking the description of hanging spiders where the flower is predominantly long spurred petals. Flower colours include yellow and orange and white through many shades of pink and red to mauve to quite dark purple.