'Waterfall' was apparently named because of the way the leaves create a cascading effect. Reddish mauve flowers are held clear of the leaves. We bought this one from Desirable Plants in the spring of 2015, and therefore have not had it long enough to fully appraise. It seems like a medium to tall growing variety of E. grandiflorum and appears quite vigorous.
General information on Epimedium grandiflorum
Distribution – Japan (Kyushu, Shikoku, Honshu and Hokiado). Northern Korea and southern Manchuria.
Description – A medium sized fairly deciduous species with widespread distribution through Japan etc. growing in deciduous woodland. It was introduced to Great Britain in the 1830s. With its wide geographical range through the various Japanese islands etc., a good deal of variation has occurred. Flower colour of the plants found in the wild varies widely: yellow, white, pink, lilac and reddish to purple. Add to this the large number of plants attributed to E grandiflorum that have arisen in cultivation and there may be hundreds of cultivars already named.
Epimedium grandiflorum 'Waterfall'