From a sign: "All the plants in this bed belong to the Euphorbia family (Euphorbiaceae), named after Euphorbus, a Greek medical doctor who lived in the first century.
"Euphorbias all have a sticky, milky, white sap which can be quite poisonous and may even blind you if it gets into your eyes. Most eastern African euphorbias are covered with thorns, especially those growing in the warm and dry areas.
"Some are neat, pin-cushion-like species, hugging rocks. Others are tall, dense, and tree-like, with thickened, succulent branches or stems. The milkweeds have finger-like stems, some with small leaves. On the Highveld, one finds finger-like species with underground stems."
From South Africa, May