A PLANT THAT almost always separates gardening snobs from gardeners is the Japanese barberry, Berberis thunbergii, an aristocrat commoner than dirt.

This is the densely twiggy 4-foot-high barberry often used for hedges. Its sharp spines discourage dogs and postmen (both of whom are much given to arranging thoroughfares through small treasures) and the shrub is handsome all year, though not evergreen.

Its little leaves, half an inch or so long and nicely oval, are good steady green and somewhat leathery or firm, turning in the fall to orange crimson and scarlet -- a display not sufficiently exclaimed over by garden writers, if I may say so, who commonly tend to be snobs themselves.

Amid the blaze of this barberry are hundreds of small scarlet oval berries that hang on even after the leaves drop around Thanksgiving time, the berries often lasting until April.

Birds don't eat them, much, and often young plants can be found near old bushes. Even when bare of leaves, the dark black-red stems are so dense that the shrub looks good in winter, and it is fine when iced with snow.

When it arrived from Japan in 1874 its beauty was instantly applauded, even before gardeners discovered it will grow in dry barren hostile ground with no fertilizer, no spraying, no care. As a result, it was soon to be seen in all manner of dismal places holding on for dear life on bleak cold windy December days in Pittsburgh and Chicago and I admit it is all too awful to think of. This may be the place to remind ourselves we live in the best place of all, right here.

Like the tree of heaven, the Ailanthus, which grows along railroad tracks in the industrial Northeast and in New York slums, the barberry flourishes in graceless places, and because of this it is neglected or even despised by many. Gardeners seem to feel that if they plant the ailanthus or this barberry or similar tough plants they will perhaps turn the garden into a wasteland.

We have never had three more fastidious gardeners than the late Reynolds Hole, Gertrude Jekyll and William Robinson, all of whom vastly admired this barberry. And the plant's only fault is that it may be seen anywhere and has no aura of rarity or vogue about it.

As Sophie Tucker once said of something else (was it Miss Tucker? I think so), its beauty has protected it, all the same, from the ravages of familiarity and the scorn of the lofty.

Now many wonderful plants have shocking defects, and really look like nothing much except for some brief moment when they are putting on their great act. Forsythias, for example, or beauty-bushes (what a revolting name for the Kolkwitzia, a name it deserves) or, to name a rarity much valued, but which is an ordinary and lusterless thing, the Davidia.

I might even mention the garden-hybrid irises, which have so many faults of foliage and habit that nobody would grow them except for the circumstance of their being the most gorgeous of all flowers.

But in contrast to all these, you have the great garden aristocrats:

Plants so well put together, so fully infused with rightness of parts and so free of shabbiness that you can only marvel that something has not gone wrong somewhere, but it hasn't.

Typical of flawless plants are the dogwood, the persimmon, the sourwood, the azaleas, the bull bay, the sweet bay, the white oak, the osmanthus, almost all hollies (except the Japanese, which are absurd and worthless things), box, yew, bald cypresses, many viburnums, some maples, some Asian witch hazels, the native red cedar and so on.

And this barberry. Indeed, most barberries. In one place, to try to clarify this business of what inherently superior plants are like, I grow a much less elegant shrub, a form of the European spindle tree called "red Cascade," which is supposed to prostrate everybody with wonder when its branches bend earthward with the weight of fall fruit. Wonderful or not (and it has thus far refused to fruit, I might add) it has distinctly dull and poor nothing-type foliage, a nondescript and unimpressive appearance generally apart from its tremendous autumn show if it ever deigns to put on the show it was born for.

I am rarely seduced by plants like that, that have only one or two fine features, and it is rarely possible that "Red Cascade" is performing so poorly because it senses my jaundiced eye towards it.

I rarely look at it without comparing it unfavorably to its adjoining superiors -- the Foster holly, the Maries viburnum, the dwarf yews, the wild mountain andromeda, the Glenn Dale and Kurume and Gable azaleas, the box and epimediums, the Asian euonymus (E. alatus, a much more elegant animal than the European) and so forth.

There are entirely too many faultless plants for any one gardener to manage even a tithe of them, and then there are all too many plants with severe faults (like 'Red Cascade' and the irises and roses and lilies and hydrangeas, zub, zub, zub) which we nevertheless lose our hearts to.

Among our human friends we often are close to people who are not nearly as grand as people we do not seek out at all, and in the same way gardeners often love plants that are by no means as full of merit as other plants that could easily be acquired in their place.

So I certainly do not say we must get rid of the faulty irises and plant the barberries, simply because the barberry is a far better all-rounder.

But I do regret hearing (or overhearing, at a local nursery) some yo-yo bumpkin sneering at this elegant barberry while hoofing on to plants with not half the barberry's merits or beauty.

There are about 450 species of barberry, and I would guess there are 200 species of barberry grown in gardens of the temperate world. You could make a beautiful garden, I suppose, of nothing but barberries and their relatives, such as nandinas and epimediums and mahonias. Indeed, some people have done it, I am told.

One barberry (among many) that I never see among us is B. darwinii, which was discovered by Darwin in southern Chile and Argentina. It is a surprising beautiful plant to have come from such a terrible place. Terrible as far as climate is concerned. No doubt the savages were good enough folk, even in Darwin's day. But you hardly expect an evergreen shrub of six feet, polished and leaves like a small holly, to appear at the very end of the world. p

It is one of the few barberries that are showy in flower (clouds of yellow) in spring. It is said to be hardy in our own climatic zone, and I have talked to a couple of local gardeners who say they have no anxiety about it during our winters.

With Darwin's barberry, as with several dozen others, the great obstacles against seeing it in gardens generally, are ignorance that it exists, shakiness of supply (I suppose you would have to buy it from the West Coast), uncertainty how to grow it (it grows well in London in ordinary semi-shade, as at the edge of a woodland) and -- worst of all -- too little space in the garden to experiment with unfamiliar plants.

This is understandable enough. In our tiny cat-runs, can we be expected to use our small budgets and space for an untried exotic, when we cannot begin to accommodate even a hundredth of the plants we know to be superb?

Barberries thus illustrate two points at once: there are barberries we do not grow because they are too common and barberries we ignore because they are not common enough, yet both classes of barberry may be finer plants than some creatures we give space to.

No barberry -- indeed no other plant on the planet -- colors more gorgeously in fall than the plain green Japanese barberry, but there are other garden forms of it that are also splendid, such as B. thunbergii atropurpurea, which has reddish purple leaves that turn crimson (with occasionally scarlet leaves here and there) and which also has the same scarlet oval berries as the green form. The purple-leaf form does not color so brilliantly as the green form in the fall, but it is as handsome as anything really needs to be.

There is also a form with rosy and variegated leaves, and a kind with acid-yellow leaves, and there are several variations among the purple sorts, like 'Knight Burgundy' which is blacker purple rather than red-purple, and 'Crimson Pigmy' which sits there in a fat little dump like a round cushion and which is, therefore, popular with some. I have always thought garden designers like this dwarf form because it takes so many of them to cover the ground. But in small sunny gardens it may introduce just the touch of reddish-purple foliage you want.

Some barberries come and go in nursery lists, among them B. wilsonae from Tibet-China with masses of salmon-colored berries. Seize it when you see it. But there is scarcely such a creature as an ugly barberry or an undesirable one.