Foraging in Cairo

Know these first

What can hurt you around Cairo in October

3 species on our hazard list have been recorded near here this month, 1 of which can kill a healthy adult. Learn these before you learn anything you intend to eat.

• Can kill2 records nearby

  Castor oil plant

  Ricinus communis

  Mistaken for

  Its mottled seeds look like beans, or like fat ticks, and children pick them up; it grows as a weed on riverbanks, roadsides and rubbish heaps across Africa.

  How to tell

  Big, glossy, hand-shaped leaves with five to eleven pointed, toothed lobes, often flushed red; spiny three-lobed seed capsules; and smooth, shiny, bean-like seeds mottled brown and grey with a small pale cap at one end.

  What it does

  Ricin. Four to eight chewed seeds are considered a lethal dose for an adult: burning mouth, then bloody diarrhoea, dehydration and collapse over several days. Seeds swallowed whole may pass unbroken, but never count on it.

• Hospital3 records nearby

  Euphorbias (milk bushes, naboom, pencil tree)

  Euphorbia (the whole genus)

  Mistaken for

  Prickly pear and other cacti — many African euphorbias are spiny, leafless succulents that look exactly like cacti — and the pencil-stick hedges of Euphorbia tirucalli around farms and villages.

  How to tell

  Break a stem: a euphorbia bleeds white milky latex at once. Cacti such as prickly pear bleed clear or slimy sap, and their spines grow from small fuzzy cushions; euphorbia spines grow singly or in pairs, never from a cushion.

  What it does

  The latex burns skin and mouth, and in the eye can cause temporary blindness. Wear gloves and eye protection near a cut plant, and never rub your eyes.

• Hospital1 record nearby

  Lantana (tickberry)

  Lantana camara

  Mistaken for

  Blackberry-like clusters of small dark berries that children pick; it smothers forest edges, roadsides and farmland across East and southern Africa.

  How to tell

  A scrambling shrub with square, prickly stems, rough leaves that smell sharp when crushed, flat clusters of tiny flowers that change colour as they age (yellow to orange, pink or red), and tight bunches of small berries ripening green to glossy purple-black.

  What it does

  The green, unripe berries are the dangerous ones: vomiting, diarrhoea and difficulty breathing have been reported in people. Livestock that eat the leaves suffer liver damage and severe sunburn.

These are recorded within about 40 km of here in this month, from verified public observations. It is not a complete list of what is dangerous — nothing is — and a species missing from it may still be in your woods. Never eat anything identified from a photograph and a description alone.