1 egg, hard-boiled 1 tablespoon finely chopped nasturtium leaves (include small flower buds and flowers if you like) 1 tablespoon finely chopped angled onion leaves (lower half of the leaf is best here, flowers definitely recommended) A generous spoonful of mayonnaise Salt and pepper to taste
Shell the hard-boiled egg and cut it into quarters. Pop it in a small bowl with the other ingredients and mash with a fork until as smooth or chunky as you desire. Put it between two slices of bread – a malty rye is particularly good, or go for thinly sliced, buttered white with the crusts cut off if you’re aiming for high tea vibes. Just don’t forget to put those crusts in the freezer so you can turn them into croutons later.
2 tablespoons coconut oil 1 large onion 4 cloves garlic 2 teaspoons of cumin 2 teaspoons of turmeric 2 teaspoons of coriander seeds 1 teaspoon garam masala ½ teaspoon of cayenne pepper 2 teaspoons of salt 1 cup red lentils 1 litre of stock (or 1 tablespoon of stock powder plus water) About 600 grams of pumpkin 4 cups of firmly-compressed mallow leaves an egg-sized piece of fresh ginger 2/3 cup of coconut cream.
mallow leaf
1. Chop the onion and garlic. Melt the coconut oil in a large, heavy-based saucepan and fry the onion, garlic and spices. 2. Chop your pumpkin into 3cm chunks. Wash the mallow leaves, then chop roughly. Add both to the pot along with the lentils, stock and salt. Cover and simmer until the mallow, pumpkin and lentils are all tender. 3. Stir in the finely chopped ginger, plus the coconut cream, and simmer, uncovered, for a further 5 minutes. Serve with pickle, a dollop of yoghurt and naan bread, or on basmati rice.
tl;dr: A bit. If you use it topically medicinally, bandage it up to keep your skin out of the sun.
One of the edible weeds we do a short profile on in The Weed Forager’s Handbook is cobbler’s pegs (Bidens pilosa). It’s not one of our favourites gastronomically, but it’s not too bad either.
The roots, leaves and flowers are strongly phototoxic. Substances isolated from the leaves can kill human skin in the presence of sunlight at concentrations as low as 10 ppm (PFAF 2007).
That’s a direct quote from the Plants For A Future database, which in turn references James Duke’s book Medicinal Plants of China (1985).
I don’t have the book but it seems to be a reference to a 1979 paper by Wat et al., “Ultraviolet-Mediated Cytotoxic Activity of Phenylheptatriyne from Bidens Pilosa L.” from the Journal of Natural Products.
The substance phototoxic to skin cells at 10 ppm is the titular phenylpetatriyne (abbreviated to PHT). The prevalence of PHT in Bidens pilosa they report as “400-600 ug/gm fresh weight.” (I.e. around 500 ppm.) In the experiment the skin cells were petridish-cultivated, then shaken around in a PHT solution for 30 minutes before exposure to the light.
If it was blended up B. pilosa that solution would need to be about 2% fresh plant matter in water to reach 10 ppm PHT. In practice I imagine it may need to be higher due to competition from all the other substances in the plant to pass into the cell membranes. So, fairly unusual circumstances.
Should we be aware of this / worried about handling Bidens pilosa? I suspect, given that skin damage is not a thing I’ve ever heard people reporting when weeding it, and googling variations on the theme of “bidens pilosa skin damage photosensitivity” brings up no anecdotes I can find, that it’s probably not an issue to be concerned about when weeding.
But if you are applying it topically medicinally (it is a traditional medicine for wound healing) it might be an issue. I did find the following reference in a Brazilian paper:
“Bidens pilosa, a herb known as hairy beggarsticks, often used in Brazil and other countries in the topical treatment of dermatosis, is frequently associated to the aggravation of the dermatologic condition by the own patient. It is described as having antifungal, antibacterial, and antiviral properties. However, it contains phenyl heptatriene, 7 a phototoxic substance. This helps to explain the high number of cases of worsening or development of eczema in areas exposed to sunlight after topical treatment (immersion baths) with hairy beggarsticks seen in dermatologic practice.”
