Devil’s Tongue (Amorphophallus konjac)

by David McDaniel

A mass of compound-seeming leaves atop squishy stalks pouring out of a large pot in the central circle of the theme garden at the National Herb Garden was labeled “Devil’s Tongue.” Replanting was simple enough, and I did not think much about the plant after that. I figured it was a non-woody shrub of sorts. I recognize that the inability to categorize the plant into defined botanical terms should have tipped me off that it has an interesting life cycle, but it was not until I was making labels that I discovered just how interesting it is.

Amorphophallus konjac is a perennial corm in the Araceae family that grows a single, highly divided leaf, and once the corm reaches maturity it sends out a single inflorescence (Mahr, n.d.). The single leaf divides into the form of a small tree that serves to gather energy for the corm to either further maturity or regenerate after production of an inflorescence. The inflorescence has thousands of flowers at the base of the spadix within the spathe. The spathe is the part of A. konjac that wraps around the central spadix almost like a collar. The spadix is home to the inflorescence at its base and protrudes from the center of the spathe. The flowers are pollinated by carrion flies that are attracted to the smell of dead animals that emanates from the inflorescence (Mahr, n.d.). This plant is native to the Yunnan Province in China, but has become popular around the world for its unique culinary uses (Flora of China, n.d.). 

The corm is an engorged stem base, shaped almost like a donut, that stores energy collected by the single leaf it sends up every year. The corm of the plant is edible, but cannot be consumed raw due to the formation of calcium oxalate crystals that cause intense discomfort in the mouth and digestive system (North Carolina Extension Toolbox, n.d.). The calcium oxalate crystals are broken down at baking temperatures; therefore, the peeled and sliced corm must be baked and then ground into a fine powder before it can be used (Fern, 2010). 

The powder, when combined with water, makes a jelly. The jelly is traditionally formulated with seaweed to give it a pleasant brine flavor. It is gray when seaweed is used in preparation but is white when prepared without. In Japan, the finished jelly product is called konnyaku, konjac (NC State Extension, n.d.). The English form of the word is pronounced like the liquor, cognac. The jelly takes on the flavor and color of any additional ingredients. Modern uses still have both traditional options, but fruit and vegetables are sometimes added for flavors used in candies and the bubbles in bubble tea. In bubble tea it is used as a replacement for tapioca when a sweet flavor, as opposed to a savory flavor, is desired. More generally, the jelly can be used as a vegan replacement for anywhere gelatin is used. It can also be used as a replacement for seafood. The seaweed preparation of konjac lends a fish flavor to dishes and is used as a vegan substitute for fish. 

Another preparation of konjac is in the form of noodles. The noodles are translucent and are known as shirataki. Shirataki noodles are low calorie, gluten free, and light on carbs (Spritzler, 2018). Keto diet circles hail them as a “miracle food” since they are like wheat noodles, but are not as carbohydrate heavy or high in calories since they are 97% water and only 3% flour (Spritzler, 2018). The noodles can be substituted in recipes that have wheat noodles, provided some limitations are considered (Spritzler, 2018). The primary limitation is the lack of flavor when prepared on their own; however, the noodles will absorb a lot of flavor in the dish when cooked with other ingredients. 

The medicinal properties of konjac come from the glucomannan in the flour, as it is a source of good carbs for gut microbiota while not being available for uptake by humans (Spritzler, 2018). Feeding gut microbiota gives konjac prebiotic properties (Spritzler, 2018). The lack of bioavailability of the glucomannan is another reason konjac is popular in keto diets (Spritzler, 2018). The glucomannan also relieves constipation and symptoms of irritable bowel syndrome (Fern, 2010; Spritzler, 2018). The mechanism that allows glucomannan to work as such a good source of dietary fiber is that it has a high rate of water absorption by weight, which allows for a higher water content in bowel movements (Devaraj, 2019). The prebiotic properties are due to the preference of healthy bacteria native to the gut for glucomannan over other available sugars (Devaraj, 2019). 

The konjac at the National Herb Garden did not flower this year, but the leaves were large enough we had to plant it in the ground since it was bursting out of the pot. There’s a good chance in the upcoming years that it will flower brilliantly and I hope to see it. After reading about all of the uses of konjac I will be on the lookout for konjac foods and candies on my grocery trips! 

Photo Credits: 1) The tree-like single compound leaf of Amorphophallus konjac (Sebastian Stabinger, via Wikimedia); 2) A group of A. konjac inflorescences, showing the collar-like spathe round the central spadix (James Steakley, via Wikimedia); 3) Close-up of the winged compound leaf (David McDaniel); 4) A packet of mango flavored konjac jelly (Open Food Facts); 5) Konjac noodles (Alpha, via Flicker)

Medicinal Disclaimer: It is the policy of The Herb Society of America, Inc. not to advise or recommend herbs for medicinal or health use. This information is intended for educational purposes only and should not be considered as a recommendation or an endorsement of any particular medical or health treatment. Please consult a health care provider before pursuing any herbal treatments.

References 

Devaraj, R. D., C. K. Reddy, & B. Xu. 2019. Health-promoting effects of konjac glucomannan and its practical applications: A critical review. International Journal of Biological Macromolecules. 126: 273-281. Accessed November 6, 2022. Available from: https://pubmed.ncbi.nlm.nih.gov/30586587/ 

Flora of China (Internet). n.d. Amorphophallus konjac K. Koch, Wochenschr. Gärtnerei Pflanzenk. 1: 262. 1858. Flora of China. Accessed November 6, 2022. Available from: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242302696

Fern, K. n.d. Amorphophallus konjac. Tropical Plants Database. Accessed November 6, 2022. Available from: https://tropical.theferns.info/viewtropical.php?id=Amorphophallus+konjac 

Mahr, S. n.d. Voodoo lily, Amorphophallus konjac. Wisconsin Horticulture. Accessed November 6, 2022. Available from: https://hort.extension.wisc.edu/articles/voodoo-lily-amorphophallus-konjac/

North Carolina Extension Toolbox (Internet). n.d. Amorphophallus konjac. NC State Extension. Accessed November 6, 2022. Available from: https://plants.ces.ncsu.edu/plants/amorphophallus-konjac/#poison

Spritzler, F. 2018. Shirataki noodles 101. Healthline. Accessed November 6, 2022. Available from: https://www.healthline.com/nutrition/shirataki-noodles-101 

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David McDaniel is the National Herb Garden intern for the 2022-2023 season where he’s digging into the herbal uses of plants, as well as learning the ins and outs of public gardening.

Culinary Creativity: Lavender Jelly

I can’t stop making jelly … I’m obsessed by the alchemy of sugar and fruit. Balsamic-strawberry with pink peppercorns. Bourbon peach. Spiced cider. Lemon thyme. Mint. Lavender.

Yes, lavender. I took a basic herb jelly recipe, changing up the herb for different products.

Oh. My. God.

Lavender has been the most inspired. My friends are in for a sublime holiday gift.

Lavender jelly is such a girl thing. It begs for an intimate garden party or sophisticated high tea with shortbread or scones. It would be tasty as a glaze for ham or topping for cream cheese spread or spread between layers of pound cake.  Maybe thumbprint cookies or jelly-filled doughnuts. I’ve seen suggestions as a garnish with lamb, chicken or turkey.

My jelly started with dried culinary lavender flowers. Grow your own, source them locally or mail order from a trustworthy farm. I ordered English lavender, Lavandula angustifolia, from Mountain Rose Herbs in Eugene, Oregon. I would have sourced the locally, but quantities were limited.

The first step in production was lavender tea. While some recipes use water, I infused lavender in apple juice. After boiling one cup of dried lavender flowers in four cups apple juice, I was supposed to steep them for 10 minutes. I was tired, so I went to bed and the flower buds soaked overnight.

Wow! When I tasted the tea in the morning, it was intense. So, I diluted it with 50 percent water.  Even then, the results were powerful. I’d say thin the tea at your discretion.

Without food coloring the product is pink-ish. With food coloring it turns a brownish-purple. With the gold of apple juice, a light lavender seems impossible. I’d suggest avoiding food coloring. For gifting a label, is important. And, in fact, should suggest uses for this culinary indulgence. My next project is developing those labels.

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Know that Mountain Rose Herbs cautions, “Similar to cilantro, some individuals perceive the taste of lavender in a manner that is undesirable within cuisine. An estimated 10 percent of the population interprets lavender to have a soapy and unsavory flavor. For this reason, it may be wise to exercise caution while using lavender as a flavoring agent.”

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What’s your favorite herbal jelly?

Does color matter?

By Paris Wolfe, Blogmaster, The Herb Society of America

Perhaps my favorite homemade jelly was made from Queen Ann’s lace. I love the novelty … the “wow” factor. I remember a soft floral flavor, the profile one associates with German-style wines. Trouble was, no one ate it. I did for a bit, but it lost its appeal.

I blame that on merchandising; specifically, its colorless appearance. People are attracted to bright colors, and that’s especially important in food. But, not just any color, the colors we associate with the food. For example, ketchup is red like tomatoes. It was a horrible fail when Heinz introduced blue and green ketchup in 2003. Too unnatural.

So what color would we perceive at “natural” for Queen Ann’s Lace jelly? I guess, if I had to choose, I might try a golden yellow much like white-grape jelly. That way it communicates what it is, while adding appeal.

But, what about mint jelly. On the grocery store shelf it’s Kelly green. In its raw, homemade form it’s yellow. Maybe if you squint you can imagine green?

So, what’s with the bright green color at retail? We associate the color of mint leaves with the color of the herb, and thus the color of the jelly. Hence, commercial mint jelly is green.

As a purist, that leaves me with a dilemma: To color or not to color? I want natural and I want appealing. Can I have both?

A google search on the web, scares me that any/all(?) food coloring causes misbehavior in children and potential for cancer in everyone. Because of that, often undocumented, and possible fear-mongering, many a mommy blogger has directions for homemade, even organic, food dye. But, spinach whizzed in a blender is outside the chemistry of my jelly recipes.

When I surfed onto the site of the slightly alarmist Center of Science in the Public Interest I found a report on food colors. This study seemed to identify green food coloring as among the most benign in a small scale experiment on mice.

Laura Dobson — master gardener, CSA coordinator, local food advocate — always has dirt under her nails.

I consulted my friend Laura Dobson of Virginia. A certified Master Gardener,  and food purist, she says:

“I would not add food coloring to anything. Period. I don’t care what color something is, even if it looks unappetizing. To me, things that are psychedelic colors have become unappetizing, such as neon orange Kraft Macaroni and Cheese, those frou-frou drinks in all colors of the rainbow or even Gatorade which people actually think is good for them. Ick. There are natural food colorings available, so if you really want to color your mint jelly, then I’d suggest using those.”

To color or not to color? What would you do?