Arrow Arum

The toxic twin of two edible pond plants. It stands in the same shallow water as arrowhead and pickerelweed, its leaves look almost identical before bloom, and every part burns the mouth severely.

How to recognize it: a stout midrib with feather veins looping inside the leaf edge, a narrow green spathe rather than a blue spike or white petals, and a leathery berry head that bends into the water.

You never plant or gather arrow arum — the point is recognition. Here is what to check, in the order that actually works in the field.

1. The veins. This is the test that settles the pickerelweed question and it works on any leaf, at any size, all season. Turn the blade over. Arrow arum has one stout central midrib with pinnate, feather-like side veins branching from it, and those side veins run out to a fine collecting vein that loops along just inside the leaf margin. Pickerelweed has no midrib at all — its veins run parallel from base to tip like the ribs of a fan. Nothing else about the two leaves is as reliable as this.

2. The shape and the stalk. Against arrowhead: arrowhead's blade is a true arrowhead with three sharp points and veins radiating out of the base into each lobe, carried on a spongy stalk that is triangular in cross-section. Arrow arum's blade is thicker, glossier and blunter, its basal lobes rounded rather than pointed, on a round, firm stalk.

3. The flower. Wait for bloom and there is no argument left. Arrow arum makes a narrow green finger-like spathe, 4 to 8 inches long, folded round a slim spadix — green on green, easy to overlook. Pickerelweed makes a violet-blue spike. Arrowhead makes white flowers with three round petals, in whorls of three.

4. The fruit. By late summer the spathe has closed into a leathery green bladder of pea-sized berries, and the whole head bends over and lowers itself into the water. Nothing else at a pond edge does that.

One rule covers the cases where you are not sure: gather nothing from a wetland stand you did not watch flower. Mark the good plants in bloom, and dig or cut only those, later.

There is no care - only separation. Leave wild stands alone where nobody forages, and where it shares a pond with plants you eat, mark it in bloom or remove it wearing gloves.

Arrow arum is a legitimate native wetland plant with real ecological value — wood ducks eat the berries, and the clumps hold pond-edge mud in place. Away from people who forage, it belongs where it grows and there is nothing to do about it.

What matters is separation from food. If arrow arum shares a pond, rain garden or wet margin with arrowhead or pickerelweed that you gather from, do one of two things. Either mark every arrow arum clump while it is in flower, when the green spathe makes it unmistakable, and leave those markers standing through the season — or take it out.

To remove it: wear waterproof gloves and eye protection, cut the tops first, then lift the vertical rhizome whole with a fork rather than chopping through it, since broken tissue releases sap. Bag the plant and the rhizome and put it in the trash. Do not compost it, do not leave cut material floating where a child or a dog can reach it, and wash your hands and tools afterwards. Collect and bin any berry heads that have washed up on the mud.

If you keep a pond where children play, the honest recommendation is simply not to have arrow arum in it — not because it is a menace to touch, but because green berries at ankle height are exactly what small children pick up.

What a raphide burn looks like and what to do about it - including the answer to the question people ask too late, which is whether cooking made it safe.

Someone has chewed or swallowed any part of it. Call poison control or emergency services immediately — do not wait to see how bad it gets. Get them to a phone or a hospital, and take a piece of the plant if you safely can. Rinse the mouth with cool water and, if they can swallow, give cold milk, ice or ice cream to soothe the tissue. Do not induce vomiting. Watch the airway: drooling, a changed voice, trouble swallowing or any difficulty breathing means call emergency services now, not later.

Symptoms begin within seconds to minutes — intense burning of the lips, tongue and throat, blistering, salivation and swelling. Most exposures are painful rather than dangerous, because the burning stops people after one bite. The dangerous cases are the ones where somebody swallowed a real quantity believing it was food.

“I cooked it, though.” A few minutes of boiling or a sauté does not destroy calcium-oxalate raphides. The only recorded preparations of this plant took days of roasting in a pit or months of drying, and even then the record is of a famine and travel food, not a reliable one. Treat any brief cooking as no protection at all.

“My hands are burning and itchy after pulling it.” Sap on skin can raise a stinging rash. Wash with soap and plenty of water, do not rub your eyes, and see a doctor if sap reached the eye — corneal injury from arum sap is a real and painful event.

“My dog chewed a leaf.” Same mechanism, same urgency. Call a veterinarian or an animal poison line; drooling, pawing at the mouth and swelling are the signs to act on.

“I gathered greens and I am not sure what was in the basket.” Throw the whole gathering out. You cannot sort a mixed basket of wetland leaves after the fact, and one arrow arum blade ruins a pot.

The original tuckahoe - a genuine famine and travel food of the eastern woodlands, and the strongest evidence there is that ordinary cooking does not make this plant safe.

Arrow arum is one of the plants recorded as tuckahoe in early accounts of the Chesapeake and the eastern woodlands, and its starchy rhizome and seeds genuinely were eaten. That history is worth knowing, because of what it actually says.

The processing was extreme. Accounts describe rhizomes roasted in covered pits for a day or more, or sliced and dried for months before being pounded into meal — the same order of effort recorded for jack-in-the-pulpit corms. Nobody boiled tuckahoe for ten minutes and ate it. The preparation was long precisely because calcium-oxalate raphides are stubborn: they are mineral crystals in a protein matrix, and they are broken down by extended heat and time, or by thorough drying, not by a quick pot.

So the historical record is not an invitation. It is the clearest available proof of the safety rule on this page: if the traditional preparation took days, a modern cook cannot shortcut it in minutes. Add that these were storage and hardship foods, gathered by people who had grown up with the plant and knew exactly which one it was, and the sensible modern conclusion is the one this catalog gives — learn arrow arum in order to avoid it, and take your wetland starch from arrowhead instead.

An eastern wetland plant, roughly zones 4-9, from New England to Florida and west to Texas - present wherever the shallow fresh water is that people forage arrowhead and pickerelweed from.

Arrow arum is native across the eastern United States, roughly zones 4 to 9, from New England and the Great Lakes south to Florida and west to eastern Texas and Missouri. Like every emergent, its range is drawn by water rather than climate: freshwater marshes, wooded swamps, tidal freshwater shallows, ditches, and the muddy margins of ponds and slow streams.

That is the same habitat, often the same square yard, as edible arrowhead and pickerelweed. Along the tidal freshwater rivers of the mid-Atlantic the three routinely grow intermingled in one stand. If you forage wetland plants anywhere in the eastern half of the country, assume arrow arum is present, learn the midrib-and-feather-veins test, and identify your stand in bloom before you take anything from it.