Brighter than the bygone reds in fabric shops on the high street, bright as bonfires, these are bloody, socialist reds hiding behind the church. Danger and luck, warning and blessing, feast and poison, say these paradox reds; there’s truth in the harmony of opposites. On the Welsh side of the River Teme, at the back of St Edmund’s church in Knighton, these are the red berries of celyn. A stone’s throw across the river into England, this is a holly tree. The hollies of the Welsh Marches are some of the oldest specimens of Ilex aquifolium in Europe, perhaps thanks to superstitions that it’s bad luck to cut them down, that they ward away storms and evil spirits, and that they have a symbolic place indoors as decorations. Trees such as this one draw the redwings, fieldfares and mistle thrushes from the far north to join local birds in the feast of the Holly King who rules from midsummer to midwinter, then yields to the Oak King. A bright, cool November light flashes over the prickles and makes the berries glow. Perhaps this is a mast year, with a bumper crop of fruit – there are other trees about with abundant berries – but a cold snap and an influx of hungry birds could see these stripped bare in no time. Poisonous to children and violently emetic, there is a curious link to something sickly in the churchyard grass. What looks at first like a splash of vomit, is – dog’s vomit, Fuligo septica, a slime mould, not a fungi but a protist – an amoeba-like, single-celled blob. These feed on other micro-organisms that feed on decaying vegetation, and hunt invisibly until heavy rain when they begin to move together uncannily, as if controlled by a swarm mind, to form a collective organism, a gelatinous mass. This then produces sporangia – yellowish, spore-bearing organs – to begin a new life cycle. These amazing creatures with a brainless mind and non-binary sexes, that can negotiate mazes and are being used to create algorithms to detect dark matter, seem stranger and more fictive than any of our superstitions.