The hottest day of summer so far, in an exceptionally fine week for haymaking. Long windrows of mown grass pattern the meadow, shimmering in the heat haze, and the still, humid air is saturated with the fragrance of drying hay. A day to celebrate one’s sense of smell, especially now, when its loss is recognised as an early symptom of Covid. We take deep, reassuring breaths.

Fifty years ago, when I was a botany undergraduate, a lecturer taught me that a nose well-attuned to the odours of plant species could be a valuable asset. Compare crushed hedge woundwort (nauseating) with marsh woundwort (pleasantly fruity), he advised, and their identity will never be in doubt again.

But the language for describing subtlety of plant scents to others, with broad-brush adjectives such as fetid, pungent or aromatic, is too vague. Often, conveying perceptions relies on comparisons with something unrelated, from shared common experience. The stench of flowers of Alexanders, a widely naturalised pot herb, was once memorably likened to that of an overflowing public urinal on a hot summer day.

Sometimes these experiences can be very personal, even generation-specific. Crushed tansy leaves remind me of a long-discontinued brand of floor polish used by my grandmother. The oil of wintergreen scent of meadowsweet leaf sap is reminiscent of green healing ointment applied by a kind primary school teacher to a bleeding knee grazed in the school playground. The fragrance of meadowsweet blossom, perfuming the air on the edge of the meadow here today, connects me with the face powder used by my late aunt Pat.

Each month in the countryside has its own bouquet of scents. This afternoon, the base fragrance of drying grass was lifted by citrusy notes of oil released by ripening hogweed seeds when I rubbed them between finger and thumb. And in the shade of trees along the riverbank, the cool, reviving tang of aniseed from crushed sweet cicely seeds and foliage put a spring back in our step just when our energy was beginning to flag in the summer heat.

Maybe Covid anxiety, with its threat of olfactory loss, might make perfumers of us all.