To one who loves the hills at every season, the blossoming is not the best of the heather. The best of it is simply its being there – is the feel of it under the feet. To feel heather under the feet after long abstinence is one of the dearest joys I know.

Scent – fragrance, perfume – is very much pertinent to the theme of life, for it is largely a by-product of the process of living. It may also be a by-product of fire, but then fire feeds on what lives or what has lived. Or of chemical action, but if there are obscure chemical processes at work in the dead stuff of the mountain, they give little indication to my nose. The smells I smell are of life, plant and animal. Even the good smell of earth, one of the best smells in the world, is a smell of life, because it is the activity of bacteria in it that sets up this smell.

Plants then, as they go through the business of living, emit odours. Some, like the honey scents of flowers, are an added allurement to the insects; and if, as with heather, the scent is poured out most recklessly in the heat of the sun, that is because it is then that the insects are out in strength. But in other cases – as the fir trees – the fragrance is the sap, is the very life itself. When the aromatic savour of the pine goes searching into the deepest recesses of my lungs, I know it is life that is entering. I draw life in through the delicate hairs of my nostrils. Pines, like heather, yield their fragrance to the sun’s heat. Or when the foresters come, and they are cut, then their scent is strong. Of all the kinds that grow on the low reaches of these mountains, spruce throws the strongest perfume on the air when the saw goes through it. In hot sun it is almost like a ferment – like strawberry jam on the boil, but with a tang that tautens the membranes of nose and throat.

Of plants that carry their fragrance in their leaves, bog myrtle is the mountain exampler. This grey-green shrub fills the boggy hollows, neighboured by cotton-grass and sundew, bog asphodel and the spotted orchis, and the minute scarlet cups of the lichens. Its fragrance is cool and clean, and like the wild thyme it gives it most strongly when crushed.

The other shrub, juniper, is secretive with its scent. It has an odd habit of dying in patches, and when a dead branch is snapped, a spicy odour comes from it. I have carried a piece of juniper wood for months, breaking it afresh now and then to renew the spice. This dead wood has a grey silk skin, impervious to rain. In the wettest season, when every fir branch in the woods is sodden, the juniper is crackling dry and burns with a clear heat. There’s nothing better under the girdle when scones are baking – unless perhaps small larch twigs, fed into a fire already banked. Once, striking thick loose snow from low juniper bushes before walking through them, I surprised myself by striking from them also a delectable fragrance, that floated on the wintry air.

Birch, the other tree that grows on the lower mountain slopes, needs rain to release its odour. It is a scent with body to it, fruity like old brandy, and on a wet warm day, one can be as good as drunk with it. Acting through the sensory nerves, it confuses the higher centres; one is excited, with no cause that the wit can define.

Birch trees are least beautiful when fully clothed. Exquisite when the opening leaves just fleck them with points of green flame, or the thinning leaves turn them to a golden lace, they are loveliest of all when naked. In a low sun, the spun silk floss of their twigs seems to be created out of light. Without transfiguration, they are seen to be purple – when the sap is rising, a purple so glowing that I have caught sight of a birchwood on a hillside and for one incredulous moment thought the heather was in bloom.

Among drifts of these purple glowing birches, an occasional rowan looks dead; its naked boughs are a smooth white-grey, almost ghastly as the winter light runs over them. The rowan’s moment is in October, when even the warmth of its clustering berries is surpassed by the blood-red brilliance of its leaves. This is the ‘blessed quicken wood’, that has power against the spirits of evil. It grows here and there among birches and firs, as a rule singly, and sometimes higher than either, a solitary bush by the rivulet in a ravine.

October is the coloured month here, far more brilliant than June, blazing more sharply than August. From the gold of the birches and bracken on the low slopes, the colour spurts upwards through all the creeping and inconspicuous growths that live among the heather roots – mosses that are lush green, or oak-brown, or scarlet, and the berried plants, blaeberry, cranberry, crowberry and the rest. Blaeberry leaves are a flaming crimson, and they are loveliest of all in the Rothiemurchus Forest, where the fir trees were felled in the 1914 War, and round and out of each stump blaeberry grows in upright sprigs: so that in October a multitude of pointed flames seem to burn upwards all over the moor.

Nan Shepherd, The Living Mountain: A Celebration of the Cairngorm Mountains in Scotland, 1977