Gardening: Well spotted!

Only once in my life have I ever thought I might have found a plant new to science (well, to gardeners at least), and I blew it. I was walking in the Lake District with my husband some years ago, when we came across an unusual primrose growing on a grassy slope. It was not a thrilling plant, it has to be said, just a common primrose, but its leaves were speckled with irregular gold markings, as if weedkiller had been applied haphazardly to them. It was not in flower, but I should be surprised if, when it was, it were more attractive or garden-worthy than the common, but lovely, Primula vulgaris. Rather the reverse. Nevertheless, I wanted it very badly, and anyone who has been in the same position will understand why.

Almost at once, however, we were paralysed by scruples and in the end decided to leave it where we found it, perhaps for sheep to graze it to extinction. But the reluctance to dig up plants from the countryside is so ingrained, that there was no real question of taking it.

If it had occurred in my garden, however, it would have been a different matter. Many of the best, and best-loved, plants that we grow have arisen either as chance seedlings growing in flowerbeds, or as "sports", that is, spontaneous mutations in part of a plant, which cause a stem to bear different-coloured flowers, perhaps, or variegated leaves. I never use a hoe in the borders, just in case such a seedling should occur, and I keep a close eye on the kinds of plants known to "sport" readily, such as roses. So far no luck, but I remain hopeful.

I was reminded this year at Chelsea Flower Show of how many valuable plants had been discovered, or rediscovered, by gardeners, after a period of apparent extinction. The Devon Group of the National Council for the Conservation of Plants and Gardens, or NCCPG for short, staged an excellent display in the marquee there, partly to celebrate the council's 21st birthday this year, and partly to alert us to how many good plants have been discovered in gardens. It was entitled, appropriately enough, "The Treasure Seekers".

Among those displayed were a horse-chestnut, Aesculus hippocastanum 'Honiton Gold', which grows in a field near Axminster, with yellow young leaves in spring; and a variegated Euphorbia characias with cream edges to the leaves, found in a Devonian's garden and called 'Burrow Silver'. Most intriguing was a highly ornamental blackberry, called Rubus rosifolius 'Coronarius', which looks like a white rugosa-type rose, with a green centre; it was introduced into this country in the early 19th century, and disappeared from view until a British nurseryman, Bob Brown, walking down a street while on holiday in Virginia, spotted it, asked for cuttings, micropropagated it, and brought it back into cultivation. I should like to have been Mr Hayles, a retired gardener who found 'Dartmoor', a superior form of the butterfly bush, Buddleja davidii, while out walking with his wife near Yelverton on Dartmoor, and risked life and limb to get a piece.

The National Plants Collections Directory, published annually by the NCCPG, includes the so-called Pink Sheet - a list, with short descriptions, of endangered and rare plants. It is worth getting hold of a copy and checking whether there is any plant in your garden that answers to a description in it. Is there any greater excitement than reintroducing a long-lost plant? I wish I knew.

The National Plant Collections Directory is available from NCCPG, The Pines, Royal Horticultural Society Garden, Wisley, Woking, Surrey GU23 69P. It costs pounds 5.95, including p&p