The Nature of Eureka: Bracken in The Burren


My last report came to you from Maine. My work, such as it is, requires that from time-to-time I’m forced to report from elsewhere, this week from a hotel room in Galway, Ireland. As in my last column from Maine, I am struck by similarities and differences between where I find myself compared with the Ozarks.

Yesterday, I was in The Burren in the West of Ireland which is a geological region of karst limestone mostly in County Clare and the Aran Islands, roughly the size of Carroll County. The word Burren derives from an Irish word meaning great rock or rocky place, and that it is. It is a beautiful, ancient landscape.

One of the plants I see in the nearby Burren, and two weeks ago in Maine, is also common in Carroll County. In fact, I’ve seen this plant almost everywhere that I’ve traveled in temperate or subtropical climates.

I’ve seen it throughout North America from Maine to Florida to California. I’ve seen it in temperate South America, China, Vietnam, much of Europe, New Zealand, Australia, Japan. It struck me as the most successful dominant weed of old abandoned Soviet tea plantations in the Republic of Georgia.

It’s one of the few plants that doesn’t rely on accidents of human history to travel wherever it wishes to go on the planet. Its reproductive spores are so tiny and light that they catch a ride aloft on random winds all over Earth and establish populations wherever they wish. It is the ultimate successful invasive native plant. It’s native here. It’s native there. It’s native everywhere. And it is a weed. It is bracken fern, also known as Pteridium aquilinum.

Bracken fern is also controversial, because it is considered desirably edible as a spring-harvested fiddlehead by some, and by others a poisonous plant, the ingestion of which should always be avoided.

Bracken fern contains varying amounts of a carcinogenic compound called ptalquiloside, which is linked to cancer in livestock and humans who eat it fresh. But the toxic compound is water-soluble, and traditional preparation methods in Japan, Korea, and elsewhere may render it safe to eat in moderation.

Surprisingly few wild plants are consumed in Ireland, which may be linked to the Irish cultural concept of “moderation.” I’ve experienced no cultural interest in moderation when it comes to food and beverage in Ireland, so not eating wild bracken fronds may just reflect a cultural bias in which moderation has no place.