Foraging in Oslo

Know these first

What can hurt you around Oslo in October

13 species on our hazard list have been recorded near here this month, 5 of which can kill a healthy adult. Learn these before you learn anything you intend to eat.

• Can kill8 records nearby

  Ragworts and groundsels (Senecio)

  Senecio (the whole genus)

  Mistaken for

  Wild greens and herbal teas — and, in the past, home-grown wheat: Senecio in the flour poisoned whole families in South Africa's George district in 1918.

  How to tell

  Daisy-family plants with yellow flower heads (with or without petals), each head wrapped in a single row of narrow green bracts, often black-tipped, and seeds carrying white fluffy parachutes. A yellow daisy you can't name does not go in the pot.

  What it does

  Pyrrolizidine alkaloids, which baking does not destroy. They block the small veins of the liver (veno-occlusive disease): pain, a swollen liver and fluid in the belly, and in many cases cirrhosis. Children are the most vulnerable.

• Can kill5 records nearby

  Yew

  Taxus baccata

  Mistaken for

  Its sweet red arils look like berries, and it lines churchyards, parks and hedges where foragers pick spruce tips and juniper.

  How to tell

  Flat, dark green needles in two rows, plain green underneath with no white stripes, and red fleshy cups open at one end with a hard seed showing. No cones, no resin smell.

  What it does

  Taxine alkaloids stop the heart. The needles and the seed inside the red flesh are poisonous, there is no antidote, and about 50 g of needles can kill an adult.

• Can kill

  4 records nearby

  Deadly galerina

  Galerina marginata

  Mistaken for

  Honey mushrooms, velvet shank, and sheathed woodtuft — all wood-growing clusters picked in autumn.

  How to tell

  Small brown cap on dead conifer wood, a ring on the stem, and a rusty-brown spore print. Honey mushroom drops a white print. Take a print before you cook anything you gathered off a log.

  What it does

  Carries the same amatoxins as the death cap in a far smaller body. A handful is enough.

• Can kill

  1 record nearby

  Small parasols (Lepiota)

  Lepiota (the whole genus)

  Mistaken for

  Shaggy parasol and true parasol mushroom, which are larger relatives worth eating.

  How to tell

  The dangerous ones are small — a cap under about 8 cm — with brown scales on a pale ground and a ring. Size is the whole distinction, and it is not a comfortable one, so the safe rule is to leave every small scaly parasol alone.

  What it does

  Several small Lepiota species carry amatoxins and have killed adults. There is no benefit that justifies the risk.

• Can kill

  1 record nearby

  Foxglove

  Digitalis purpurea

  Mistaken for

  Comfrey and mullein at the rosette stage, both of which are gathered for tea.

  How to tell

  Foxglove leaves are finely toothed with a strongly netted underside; comfrey leaves are untoothed and bristly, and mullein is thickly woolly and soft as felt.

  What it does

  Cardiac glycosides. A cup of tea made from the wrong rosette has killed.

• Hospital

  42 records nearby

  Fly agaric

  Amanita muscaria

  Mistaken for

  Rarely mistaken once it is open — but the buttons, before the cap expands, look like white eggs and get picked as puffballs.

  How to tell

  Cut any 'puffball' in half. Solid white all the way through is a puffball; the outline of a cap, gills and stem inside is an Amanita button.

  What it does

  Ibotenic acid and muscimol: nausea, then confusion, agitation and deep sedation for several hours. Not usually fatal, but genuinely dangerous in children.

• Hospital

  10 records nearby

  Bittersweet nightshade

  Solanum dulcamara

  Mistaken for

  Its red berries get picked as currants or tomatoes by children.

  How to tell

  Purple flowers with a yellow beak, leaves with a pair of small lobes at the base, and berries that ripen green to orange to red on the same cluster.

  What it does

  Solanine: burning throat, vomiting, and in a child, worse.

• Hospital

  5 records nearby

  Red elderberry

  Sambucus racemosa

  Mistaken for

  Common elderberry, which is gathered in quantity for syrup and wine.

  How to tell

  Bright red berries in a domed, cone-shaped cluster. Edible elders carry blue-black berries in a flat-topped cluster.

  What it does

  Raw berries, and the seeds, stems and leaves of all elders, carry cyanogenic compounds. Red elder is the one that reliably makes people sick.

• Hospital2 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.

• Hospital

  1 record nearby

  Panther cap

  Amanita pantherina

  Mistaken for

  The blusher and other brown Amanitas some foragers eat.

  How to tell

  Brown cap with white warts, a ring, and a distinct rim at the top of the bulbous base. The blusher stains pink-red where damaged; this does not.

  What it does

  A stronger dose of the same compounds as fly agaric, with more hospital admissions and occasional deaths.

• Hospital

  1 record nearby

  Sulphur tuft

  Hypholoma fasciculare

  Mistaken for

  Honey mushrooms and other autumn clusters on stumps.

  How to tell

  Sulphur-yellow to greenish gills and a bitter taste on the tip of the tongue. Honey mushroom has white to cream gills and a white spore print.

  What it does

  Prolonged vomiting; in quantity it has caused liver damage.

• Unpleasant

  3 records nearby

  Buttercups

  Ranunculus (the whole genus)

  Mistaken for

  Young greens gathered in damp meadows, and marsh marigold.

  How to tell

  Glossy five-petalled yellow flowers; the leaves are acrid and burn the tongue when tasted raw.

  What it does

  Blisters the mouth and skin. Cooking destroys it, which is why marsh marigold is always boiled.

• Unpleasant

  1 record nearby

  Common buckthorn

  Rhamnus cathartica

  Mistaken for

  Chokecherries and wild blueberries — it is everywhere in eastern hedgerows.

  How to tell

  Thorn-tipped twigs, leaves with curved veins running to the tip, and black berries with three or four seeds. Chokecherry has one stone.

  What it does

  A powerful laxative, which is where the name comes from. Not dangerous, but a memorable mistake.

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.