The Horse Chestnut of Parc d'Egmont

The horse chestnut is one of the most planted trees in Europe and one of the rarest in the wild. Its entire natural range is a scatter of mountain ravines in northern Greece, Albania and North Macedonia, a few thousand trees in gorges, out of which sixteenth century collectors carried it to Istanbul, then to Vienna, then to everywhere. Conkers turned it into a children's institution across a continent; the wild population is small enough to be listed as threatened. This one is 3.08 metres round with a crown fifteen metres across, on lawns closed in on all sides by the buildings of the Sablon. Brussels ranks it ninetieth of its species in the region, which for a tree this common is a respectable place to sit. Being planted everywhere has cost it. Since the 1990s the horse chestnut leaf miner has spread across Europe, a moth whose larvae tunnel the leaves until they brown and curl by August, so most chestnuts on the continent now look half dead two months before autumn without actually being ill. Bleeding canker is the serious one, and the one that kills. The flowers go up like white candles in May. The conkers come down in late September, which is the only fortnight of the year anybody looks at the ground under this tree.