Sting- a- Little? Here’s Why

Raw arrow roots

I have peeled Arrow roots since I was 12 but for the first time, after peeling them this week it felt like I had come in contact with the stinging nettle!

I started itching and had very terrible burning sensation. I was wondering if somehow an insect had crawled on me without me noticing but I was wrong. It was pointed out to me that I had judged a book by it’s cover and in a fascinating turn of events, I had judged wrongly.

Fresh arrow root tubers have needle-like calcium oxalate crystals inside the plant. The fresh arrow roots have microscopic crystals called Raphides which are tiny, sharp and made of calcium oxalate. These raphides are technically a defense mechanism against animals and insects: essentially to prevent the animals from eating them. Luckily for us, homo Erectus did us justice by discovering and using fire. Cooking the arrow roots softens the crystals and breaks down the irritating compounds.

When you peel the arrow roots, the cells break open- the raphides shoot out like microscopic needles- they pierce the skin on your hands. This in turn causes tingling, itching and a mild stinging sensation. You may notice stronger burning if your skin is dry or sensitive, you have tint cuts on your hands or you are peeling many arrow roots at once.

This could also happen if you peel raw taro, raw yam or come in contact with a stinging nettle. Pineapples have raphides too!

You can prevent the stinging by peeling under running water, rubbin hands with oil before peeling or wearing gloves if you are handling a lot.

In essence the plant is harmless, just defending itself- Do you know any other defence mechanisms that plants, animals or human use?