Undoubtedly one important element is the gigantic individual leaf. The conventional way of getting this effect is to set out banana plants, which are generally torn to shreds by a storm.
The most wonderful hardy plant of this type in England is the Gunnera, a water side plant with leaves often six feet across and sometimes ten. (See plate 97.) A New Jersey nurseryman claims that is it hardy with protection as far north as New York, but I doubt if it will ever thrive north of Virginia. The nearest we can get to it is Rheum Collinianum, which is the least like a rhubarb of all the many species I saw at Kew and elsewhere.
The grandest hardy trees with big leaves is Magnolia mac-rophylla, which has leaves a yard long and flowers a foot across. Long Island is about the limit of its hardiness.
The catalpa, paw paw, and empress tree, or Paulownia, have a tropical appearance, and their leaves are about a foot across. The gardeners have a trick of growing Paulownias in a formal bed and cutting them down every year, by which plan they get the biggest leaves. This seems to me a poor kind of beauty compared with the grand trees one sees at Flushing, L. I., especially when they are covered with their royal flowers. The bedding system sacrifices all the bloom.
Among perennial herbs with huge leaves are the two species of Petasites pictured on plate 106 one of which has leaves about four feet long. The heart-shaped leaves and yellow flowers of Senecio Clivorum are shown on plate 102, and a gigantic Crambe covered with misty white bloom on plate 78. There are several species of plume poppy, or Bocconia, that have leaves like those of a fig.