This section is from the book "Culinary Herbs", by M. G. Kains. Also available from Amazon: Culinary Herbs, Their Cultivation, Harvesting, Curing and Uses.
As garnishes several of the culinary herbs are especially valuable. This is particularly true of parsley, which is probably more widely used than any other plant, its only close rivals being watercress and lettuce, which, however, are generally inferior to it in delicacy of tint and form of foliage, the two cardinal virtues of a garnish.
Parsley varieties belong to three principal groups, based upon the form of the foliage:
(1) Plain varieties, in which the leaves are nearly as they are in nature;
(2) moss-curled varieties in which they are curiously and pleasingly contorted; and
(3) fern leaved, in which the foliage is not curled, but much divided into threadlike parts.
The moss-curled varieties are far more popular than the other two groups put together and are the only ones used especially as garnishes with meat dishes in the hotels and restaurants of the large cities. The plain-leaved sorts cannot be compared in any way except in flavor with the varieties of the other groups. But the fern-leaved kinds, which unfortunately have not become commercially well known, surpass even the finest varieties of the moss-curled group, not only in their exquisite and delicate form, but ill their remarkably rich, dark-green coloring and blending of light and shade. But the mere fact that these varieties are not known in the cities should not preclude their popularity in suburban and town gardens and in the country, where every householder is monarch of his own soil and can satisfy very many aesthetic and gustatory desires without reference to market dictum, that bane alike of the market gardener and his customer.
Several other herbs-tansy, savory, thyme, marjoram, basil, and balm-make pretty garnishes, but since they are not usually considered so pleasant to nibble at, they are rarely used. The pleasing effect of any garnish may be heightened by adding here and there a few herb flowers such as thyme or savory. Other flowers may be used in the same way; for instance, nasturtium.
There is no reason why herbs so used should not be employed several times over, and afterwards dried or bottled in vinegar if they be free from gravy, oils, fats, etc., and if in sufficient quantity to make such a use worth while. Other pretty garnishes which are easily obtained are corn salad, peppergrass, mustard, fennel, and young leaves of carrot. But surpassing all these in pleasing and novel effects are the curled, pink, red and white-leaved varieties of chicory and nasturtium flowers alone or resting upon parsley or other delicate foliage. So much by way of digression.