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COOKING ETHNOBOTANY FOOD ANTHROPOLOGY

My new book on eating ferns – why eat ferns, are they toxic and what is pteridophagy?

11th March 2022

Why eat ferns?

Ferns are plants, and you can eat them just as you can eat other plants. Firstly, some ferns have historically been used to supply people with calories, including the rhizomes of bracken and some woodferns. Nowadays they might be used in a survival situation or in times of catastrophe (but see the chapter on bracken for information on its carcinogenicity).

Secondly, young spring fern shoots are easily available green vegetables with a nice texture, and, like other green vegetables, they contain vitamin C, folic acids, carotenoids, fibres etc. Dvorakova et al. (2021) found that the vitamin C and carotenoid content in ferns is similar to that of ordinary green vegetables, but ferns contain more antioxidants.

And I have some extra good news, especially if you are on a vegan diet. Fern fronds contain long-chain polyunsaturated fatty acids (LC-PUFAs) – arachidonic acid (20:4n-6, ARA), eicosapentaenoic acid (20:5n-3, EPA), sciadonic acid (5,11,14-20:3, SCA), juniperonic acid (5,11,14,17-20:4, JA) and other acids (Nekrasov et al. 2019; Nekrasov and Svetashev (2021)). LC-PUFAs are considered important nutrients due to their role in human physiology and difficulty with their iosynthesis by our bodies. The major LC-PUFAs are ARA, EPA, and docosahexaenoic acid (22:6n-3, DHA). LC-PUFAs are precursors of various signalling molecules and take part in the regulation of membrane properties. We usually obtain LCPUFAs from external sources, though some endogenic synthesis from the corresponding essential fatty acids is also possible.

Moreover, ferns are aesthetically pleasing. The fiddlehead or crozier shape gives green fern dishes a particularly interesting appearance. They also have a nice, crunchy texture, something my Chinese friends would call cui. This is what makes them so appreciated in Chinese, Japanese and Korean cuisine.

Most ferns are perennials, so they can form a wonderful part of a permaculture garden. For those not acquainted with botanical terminology – perennials are plants which, although they may lose leaves in winter, can produce new shoots in spring from their ‘permanent’ root or rhizome (underground stem), so there is no need to sow or plant them anew every year. Ostrich fern is especially suitable for temperate permaculture gardens, and vegetable fern for the tropics, as they have the best taste. Given the right conditions (semi-shaded, fertile and moist), ostrich fern can create an extensive stand in your garden for you to harvest each spring. Many ferns are shade resistant and can grow in parts of forest gardens that very few other wild vegetables are able to survive in.

Toxicity

Like many flowering plants, ferns and horsetails contain the enzyme thiaminase, which breaks up thiamine (vitamin B1). The frequent consumption of raw or undercooked ferns can cause beri-beri illness (vitamin B1 deficiency). Thiaminase is quite temperature stable, but its content can probably be greatly reduced by cooking and discarding the water, which is part of many traditional recipes. Moreover, the occasional consumption of tiaminase-containing plants is not dangerous. Such foods pose a problem only if they become everyday culinary ingredients.

Some ferns may contain carcinogenic agents. This is mainly the case with bracken (Pteridium), which contains ptaquilioside, one of the most carcinogenic of any natural substances known in nature. Fortunately, out of 21 fern species, mainly native Danish ferns, Rasmussen and Pedersen (2017) found the ptaquiloside to be present only in bracken and none of the other ferns. On the other hand, 19 of 31 fern species tested by chemotaxonomic methods in Japan are known to contain ptaquiloside and/or related carcinogens (Potter and Baird 2004). In my opinion we need more studies on fern carcinogenity to dispel fears abou it. The issue of bracken carcinogenicity is discussed in detail in the chapter on bracken. Here I should only mention that flour extracted from bracken rhizomes has not been found to be carcinogenic (Rasmussen 2021), and boiling the fiddleheads and discarding the water should also remove considerable amounts of the toxin but not all of it (Rasmussen 2021). Surprisingly, crosiers with no carcinogens  were found in the USA (Rasmussen (2021) and New Zealnd (Rasmussen et al. 2008), indicating a potential for commercial production of ptaquiloside-free fronds.

 Ferns have been consumed for millennia in many countries, and even if some studies correlate their life-long consumption with increased gastro-intestinal cancers, in my opinion the argument is weak. Occasional consumption of traditionally made fern dishes should not harm you. I cannot guarantee you will live to ninety, but I have personally eaten ferns hundreds of times. In this place I would like to quote Wilson et al. (1998):

When considering the possible harmful properties of bracken, distinguishing between the concepts of hazard and risk is useful. A hazard is a set of circumstances that may have harmful consequences; risk is the probability of harmful consequences occurring from a hazard. For example, lightning is a hazard, but the risk of being struck by lightning is very small, approximately one in ten million.

Pteridophagy

            The practice of eating ferns can be called ‘pteridophagy’ (analogous to similar terms such as ‘geophagy’ – eating soil, or ‘entomophagy’ – eating insects). Where is pteridophagy found? Although there are many areas of the world where a single species of fern is or was eaten, in some regions people have specialized in eating ferns and consume more species. These are usually places with damp climates where at least for some part of the year ferns can obtain enough moisture to thrive. Here we should mention east and south-east Asia, including Indonesia and the Philippines, parts of Africa, and, in the past – New Zealand and the Pacific coast of North America. However, the inhabitants of some moist areas of the world that are rich in ferns have never eaten them. This is the case with Great Britain as well as South America. In the province of Misiones in Argentina, only one species of fern is eaten (Pecluma pectinatiformis (Lindm.) M. G. Price), whereas about 50 species are used medicinally (Keller et al. 2011). For comparison, 23 species of pteridophytes are used in the cuisine of NE India (Yumkham et al. 2017) and 26 species in Nepal (Ojha and Devkota 2021), while at least 52 species of ferns are eaten in China (Liu et al. 2012). This shows the importance of cultural factors. In some areas of the world, the edibility of ferns has never been discovered due to a distrust in green foods, known as herbophobia (Łuczaj 2008a). The Amazon, where people generally refuse to eat leaves (Katz et al. 2012), is a good example of this.

For references see my newly published book:

The book presents around 80 species of edible ferns and horsetails used across the globe. As ferns often have large geographic ranges, knowledge of them may also be useful for you when travelling to distant countries. Such issues as possible toxicity, detoxification procedures, cooking techniques and basic identification principles for ferns are also discussed.


A whole spectrum of possible fern foods is presented: from green fiddleheads in spring, starch from bracken rhizomes and the pith of tree ferns, to eating polypody fern rhizomes as a sweet snack. As ferns often have large geographic ranges, knowledge of them may also be useful for you when travelling to distant countries.


A special effort was made to encompass the edible species commonly found in North America and Europe. The book includes plenty of examples from areas in temperate and tropical Asia, where the author took part in several ethnobotanical expeditions and witnessed local people gathering ferns for food and making dishes out of them. The fascinating tradition of using ferns in New Zealand was not neglected either. The book also presents traditional fern cooking recipes from all over the world.

Writing this post I would also like to recommend a book about wild foods of Japan (Eating Wild Japan) writtinen by Winifred Bird. She shared two recipes with me and I was greatly inspired by her book containing lots of info on fern uses in Japan.

https://www.winifredbird.com/


ASIA COOKING ETHNOBOTANY EUROPE POLAND

Kharet, rząsy and pua… Can we digest pollen? Will hazel and cattail cakes become a new-old hip health food?

7th March 2021

I wonder why so few foragers ask about pollen. Actually, the view on the nutritional availability of pollen to us varies extremely among nutritionists and I wanted to systematize it by quoting the available few sources.

In the nineteenth century Poland’s poor peasants had a term przednówek, i.e. “before-the-new” for spring starvation or food shortages. They were saving on the last stores of grain by collecting hazel  (Corylus avellana) catkins covered by pollen (technically they are male inflorescences). These catkins were called rzęsy or rząsy (local name for eye-lashes). They added them to bread dough. This usually happened in March (or even February) but, later at the turn of March and April, people would also consume male catkins of sallow (Salix caprea) which were supposed to be good against colds (Łuczaj 2021).

Another pollen plant used for foraging is cattail (Typha). It produces a lot of pollen which has been used in some countries for food, i.e. in the Middle East, south-east Asia and by Maori in New Zealand and Native Americans in both North and South America (Prendergast et al. 2000). Also maize pollen was collected by the Indians  (Prendergast et al. 2000)

Pollen is very rich in nutrients. The pollen of insect pollinated plants is more nutritious than this of wind pollinated plants but is much scarcer (Linskens and Jorde 1997). According to one study pollen contains 11% fat, 36% carbohydrates and 23% proteins, being similar to dry pulses (Linskens and Jorde 1997).

Typha dominegenis pollen is widely sold in southern Iraq round the confluences of the Tigris and Euphrates. This pollen mixed with sugar and steamed is known as kharet and sold in the souks of Kuwait (Prendergast et al. 2000).  Typha is also known as food among the Maori of New Zealand, known there as pua (Prendergast et al. 2000). Maori would wrap leaves around the mixture of cattail pollen and water and steam it in a hangi (an earth oven). Colenso (1880) described the cooked cake as “sweetish and light, and reminds one strongly of London gingerbread”. Maybe I should actually cite everything who wrote about this food:

“Another highly curious article of vegetable food was the pungapunga, the yellow pollen of the raupo flowers—the common bulrush, or cat’s-reed mace (Typha angustifolia). This was collected in the summer season, when the plant is in full flower, in the wet swamps and sides of lagoons, streams, and lakes. I have been astonished at the large quantities of pollen then obtained. On one occasion, more than thirty years ago, I had several buckets full brought me by the present chief, Tareha, in his canoe, some of which I sent both raw and cooked to the Kew Museum. In appearance in its raw state it exactly resembles the ground yellow mustard of commerce, and when put up into bottles would be mistaken for it. It is obtained by gently beating it out of the dense flowering spikes. To use it as food it is mixed up with water into cakes and baked. It is sweetish and light, and reminds one strongly of London gingerbread. Dr. Sir. J. D. Hooker informed me that when he was in India he found the natives of Scinde making a precisely similar use of it.” (Colenso 1880: 26).

Pollen walls are made of two layers: intine and exine. Exine is extremely hard, but can have apertures: they are regions of the pollen wall that may involve exine thinning or a significant reduction in exine thickness. They enable shrinking and swelling of the grain caused by changes in moisture content. The digestive enzymes can enter pollen walls only through the apertures. Franchi (1997) carried out experiments on the digestion of hazel (Corylys avellana) and poppy (Papaver rhoeas)pollen. They were based on in vitro digestion with enzymes and environments similar to human digestive system (pepsin, papain and diastase, pancreatin and pancreatic lipase in optimial pH conditions). Hazel has relatively thin intine. After 24 treatment only 3% carbohydrates and 59% proteins in hazel pollen were digested. This shows the small availability of carobohyrates and relatively high availability of proteins. Only high pH treatment with pancreatic enzymes has an effect, whereas the acidic pH of stomach does not affect pollen.

Let’s look at bees, As Roulston and Cane (2000) write “Pollen digestion has been studied most extensively in bees, but a complex and somewhat confusing set of interpretations has emerged. Adult bees possess a crop, in which nectar and pollen may mix, thus providing a pre-treatment that could lead to germination or pseudo-germination. The crop leads through the proventricular valve to the gut, a region that differs substantially in osmotic pressure from the crop. Thus, pollen consumed by adult bees is subjected to immersion in a sugar solution followed by an abrupt osmotic gradient. In contrast, larval bees have no crop. Pollen enters the gut without internal exposure to nectar sugars or sudden changes in osmotic pressure. The pollen consumed by larval bees, however, is part of a food provision including a large quantity of nectar. Thus, larval pollen has been exposed to a liquid sugar environment prior to ingestion. For most bee species, larvae consume the pollen within a few ways of pollen collection. For honey bees, however, pollen may be stored in the hive for an extended period of time.”

The best way to enable the digestion of pollen is to cause germination and pseudo-germination by cracking pollen walls by osmotic pressure. No wonder in Iraq cattail pollen is mixed with sugar. Bees do it similarly storing the pollen with nectar. In Poland hazel catkins were used in sourdough bread which may also have had an effect on the digestibility of the pollen. The conclusion is the interior of pollen grains can be accessed by humans and partly digested. It can probably be highly increased by creating a high osmotic pressure storing the pollen in sugar (confirmed by traditional use) or salt (my hypothesis).

If you want to read about other Polish famine food, you are welcome to buy my book:

Literature

Prendergast, H.D., Kennedy, M.J., Webby, R.F. and Markham, K.R., 2000. Pollen cakes of Typha spp.[Typhaceae]-‘lost’and living food. Economic Botany, 54(3), pp.254-255.

Arenas, P. and Scarpa, G.F., 2003. The consumption of Typha domingensis Pers.(Typhaceae) pollen among the ethnic groups of the Gran Chaco, South America. Economic Botany, 57(2), pp.181-188.

Morton, J.F., 1975. Cattails (Typha spp.)—weed problem or potential crop?. Economic Botany, 29(1), pp.7-29.

Franchi, G.G., Franchi, G., Corti, P. and Pompella, A., 1997. Microspectrophotometric evaluation of digestibility of pollen grains. Plant foods for human nutrition, 50(2), pp.115-126.

Linskens, H.F. and Jorde, W., 1997. Pollen as food and medicine—a review. Economic Botany, 51(1), pp.78-86.

Roulston T.H. and Cane, J.H., 2000. Pollen nutritional content and digestibility for animals. Pollen and pollination, pp.187-209.

Colenso, W. 1880. On the vegetable food of the ancient New Zealanders before Cook’s visit.
Transactions the New Zealand Institute, 12: 1-38

Łuczaj, Ł. 2021. Foraging in Eastern Europe: Wild edible plants in Polish traditional cuisine. Pietrusza Wola.

Many thanks to Kim Walker for sharing her photo of hazel catkins.

COOKING ETHNOBOTANY FOOD ANTHROPOLOGY

Banana and sweet flag

9th January 2019

Among thousands of plant species that are similar to each other, there are some characteristic ones that are difficult to mistake, and at the same time incredibly useful. The banana, for example. The banana is a large plant that can reach over a dozen metres in height, but it’s a gigantic perennial rather than a tree.

It is generally known as a plant with edible fruits. Its flowers are also edible and are sold as a vegetable in the markets of southern Asia, e.g. in Thailand, Laos or Cambodia. The leaves can be used in many ways, as natural plates for meals (India), for rolling up dishes that are roasted on hot coals, or even as short-term hut coverings. The banana seems to be hard to replace. Its mealy fruits with a unique taste and massive, non-poisonous leaves make it a plant of great value. In our climate, we could use other large leaves instead of banana leaves, but when we look around us, there are not all that many plants with big leaves to choose from. Horseradish works really well. It is actually traditionally used in Poland for baking bread on and its leaves are wrapped round fish grilled in fire. My daughter loves to eat grilled sausages and hold them in horseradish leaves.

What other leaves were used in Poland for baking bread on? As research by the Polish Ethnographical Atlas has shown, in addition to horseradish, cabbage was widely used, along with the fragrant leaves of sweet flag (Acorus calamus, also called calamus) in the north-east. Much less often, maple, sycamore, and oak leaves were used in some villages.

Vuknius-style sour dough rye breadwith sweet flag leaves on the bottom side

I’ve also heard of the use of grape vines for this, which is probably a more recent fashion, but may well be a traditional practice in the South, as after all both the Balkans and the Middle East are famous for their stuffed grape leaves, dolma or sarma. Just like we use cabbage for our Polish gołąbki, the Southeners in the Balkans, Turkey and the Middle East use grape vines, the Romanians and the Hutsuls stuff the bitter leaves of coltsfoot, while in Moldova they even used to use marsh marigolds for this purpose.

Actually, once I took part in a project reviewing all the leaves used for food wrapping in the former Ottoman empire and we managed to get to 82 species! For more details see here:

Dogan, Y., Nedelcheva, A., Łuczaj, Ł., Drăgulescu, C., Stefkov, G., Maglajlić, A., Ferrier, J., Papp, N., Hajdari, A., Mustafa, B. and Dajić-Stevanović, Z., 2015. Of the importance of a leaf: the ethnobotany of sarma in Turkey and the Balkans. Journal of ethnobiology and ethnomedicine, 11:11:26. https://ethnobiomed.biomedcentral.com/articles/10.1186/s13002-015-0002-x

Romanian-style sarma rolls made with coltsfoot (Tussilago farfara) leaves in my cooking classes

Why, when writing about naturalness, am I writing about stuffed leaf dishes? Because the leaf as an architectonic product or a substitute for paper or vessel is something natural, deeply primitive. Before bread was made, rice was cooked or stuffing it in leaves was invented, meat, fish, insects and bulbs had been roasted on embers.

Besides roasting on the surface of the ground, the practice of pit cooking is also widespread among primitive people even of places very far away from each other. The Maori, Australian Aborigines, and Native Americans from the coast of the Pacific all did this.

They would make a pit, often surrounded by stones, in which they would light a fire and then remove at least some of the hot embers. They would make a layer of green leaves with bulbs or meat between them. Meals cooked in such a way have an amazing aroma and usually cook evenly (it is easy to burn a lot of things when roasting them over a fire). Another strength (and at once weakness) of this method is the long preparation time. We put the produce in in the evening, and breakfast is ready for us in the morning. Burying food in the ground is also a primitive method of its preservation. In Poland, too, cabbage used to be pickled directly in pits, similarly to how the people of Siberia prepared wild plants. There were also cases of meat being conserved by burying a whole animal underground. Peat is especially useful for this purpose. Mammoths conserved in peat, which are probably still good to eat, have been found many times in Siberia. A good stomach can take a lot… Once, during a botany class, I stole a piece of coconut from a friend. I was surprised that the meat was so hard (although it did taste of coconut). Only then did I notice a stamp with the Russian two-headed eagle on the shell – Carskiy Imperatorsky Universetet (Tsars Imperial University). It was a museum specimen from the end of the nineteenth century.

ASIA ETHNOBOTANY FOOD ANTHROPOLOGY

Seven Spring Herbs

8th January 2019

On the seventh of January, the Japanese celebrate a special holiday, nanakusa-no-sekku 七草の節 (The Festival of Spring Herbs), which marks the end of the New Year festivities. Nowadays, most Japanese people buy these plants in the supermarket only once a year, but until quite recently these wild weeds were collected throughout the winter and spring on an everyday basis. The tradition originally concerned the seventh day of the lunar year but was moved to the seventh day of the European calendar, which means that in some areas in the North it may be more difficult to collect these species for the Festival. However, most of Japan has quite a mild climate and some weeds can still be found in the fields in winter, only temporarily covered by snow.

Haru no nanakusa is served as a simple rice gruel with boiled herbs (nanakusa-gayu). The number seven is very important to the Japanese and has magical connotations. Usually the following plants are mixed in nanakusa:

  1. seri 芹 (せり) (Asian dropwort Oenanthe javanica ssp. stolonifera) – beware that the European dropwort O.croccata is extremely poisonous, whereas its Asian counterpart can be eaten)
  2. nazuna 薺 (なずな) (shepherd’s purse Capsella bursa-pastoris) – a common weed throughout Eurasia
  3. gogyo 御形 (ごぎょう) (jersey cudweed Gnaphalium affine)
  4. hakobera 繁縷 (はこべら) (common chickweed Stellaria media) – a common weed throughout Eurasia and beyond
  5. hotokenoza 仏の座 (ほとけのざ) (henbit dead-nettle Lamium amplexicaule)
  6. suzuna 菘 (すずな) (field mustard Brassica campestris ssp. rapa), now called kabu (蕪)
  7. suzushiro 蘿蔔 :(すずしろ) (radish Raphanus sativus var. hortensis), now called daikon (大根)

There may be deviations from this list in different parts of Japan, depending on local traditions and the plants’ availability. For example, mugwort Artemisia sp. can also be used. The custom came from China around the 8th century. It was first introduced bu the royal court and then became popular among all the inhabitants.

If you want to know more about traditional foraging in Japan I highly recommend you the book by Winifred Bird published in 2021 in Berkeley (Stone Bridge Press). Bird lived several years in Japan and wrote someting edging journalism, a foraging guide and and an ethnobotanical review. A masterpiece.

On the morning of January the seventh or on the eve of this day, a spoon for eating rice and/or a wooden mortar are placed on a chopping board, indicating an auspicious direction, and a song with the words: „before birds from the Continent come to Japan, we are going to collect nanakusa” is sung. The herbs are chopped while chanting.  

This film shows hitting the weeds with seven kinds of tools:

And another film:

Shepherd’s purse is one of the most widely collected and eaten wild vegetables. It’s not always wild. It can easily be grown from seeds and cultivated like a normal vegetable. It’s especially popular in Shanghai, where you can easily buy ji cai hou dun dumplings. There’s also a beautiful legend to do with Shepherd’s purse that was what first brought me to China.

I was always fascinated by this country. When I was three, I tried to learn Chinese characters. Later, I became very interested in the Chinese art of Feng Shui. When temporarily living in Norwich, England, I rented a room to a Chinese student, who taught me Chinese. This made me regain my interest in this place and two years later, in 2005, I bought a flight to Beijing. However, my main destination was a suburb of the ancient city of Xi’an, a place called Hanyao. I had read about the Hanyao legend in a book called “Road to Heaven. Encounters with Chinese Hermits” by Bill Porter.

Here’s the legend: Wang Pao Ch’uan was the youngest daughter of a prime minister from the T’ang Dynasty. He wanted to marry her to a politically suitable man, but she kept refusing all of the candidates. Eventually, her father made all the men who wanted to ask for her hand gather together, and she was supposed to climb the Great Goose Pagoda and throw a ball of silk from it.

Great Goose Pagoda in Xi’an

The man who would catch the ball would become her fiancé. She saw a poor traveller, P’ing-kuei, standing in the crowd. She had met him the day before and threw the ball to him. But her father did not respect her choice and the young couple had to leave the palace. They were forced to settle in an empty cave in a loess cliff that was formerly used for making pots. Unfortunately, a war with Tanguts from the North broke out soon after they had settled there, and P’ing-kuei joined the army. One of the prime minister’s sons-in-law organized a trap and P’ing Kuei was captured and imprisoned by the enemy. In spite of receiving the news of her husband’s death, Pao Ch’uan faithfully waited for his return. P’ing Kuei came back 18 years later to find her collecting shepherd’s purse. She had been eating it all the time throughout those long 18 years. Now the place is a small Daoist temple, and inside it a wax figure cabinet which depicts the story. They are also meant to serve shepherd’s purse dumplings, though I couldn’t find any when I was there in September 2005.

The gate of Hanyao in 2005

A loess cliff in Hanyao, a very typical feature of central Shaanxi landscape
One of hermit huts in the cliff
A cleaning lady guided me around
This is where Wan Pao Ch’uan lived
A holy pine tree
Wan Pao Ch’uan and her husband
A Demon House from Hanyao
Another part of the Demon House story