Underfoot: Tearthumb

By Susan Sprout

In the 1800’s, Ralph Waldo Emerson, an American poet and philosopher, wrote that weeds are just plants whose virtues haven’t been discovered yet. I do try to be thorough as I learn about various plants, but researching Tearthumb did not turn up many virtues. It is edible, cooked or raw; berries, too. Birds and ants like the seeds and disperse them; chipmunks, squirrels, and deer eat it. However, since its accidental introduction in northeast US in the 1930’s, Asiatic Tearthumb has thrived so well that it’s been designated as a noxious, aggressive, highly invasive weed in many states, including ours. 

Mile-a-Minute’s slender, reddish stems can grow up to thirty feet a year. Its triangular green leaves have barbed mid-ribs that along with its prickly stems, help hold it while climbing towards the light, shading out, and killing other plants as it goes. Do not grab onto Devil’s Tail with your bare hands as it will live up to its other name and tear your thumbs. Better double glove! 

Look for Giant Climbing Tearthumb along roads, crawling and sprawling in thickets, and uncultivated open fields resulting from both natural and human causes. This member of the Buckwheat Family (Polygonaceae) loves the things we do to the soil – the digging, the clearing, the farming, the dumping – and will move right in. Another identifying feature of Asiatic Smartweed are its fruits which can be all different colors – green, blue, red – hanging together on the stem ends like tiny bunches of grapes. Since Persicaria perfoliata likes moist soils, too, you can find it frequently hanging over waterways where it will persist until after the first frost. Its pretty fruits are buoyant, able to float for up to nine days, providing another seed dispersal method.

Did you find all of the common and scientific names of Tearthumb in the text!  If you did, Bravo! Maybe its virtue is to show that plants can have many names!

Here are the common names of Persicaria perfoliate:
*Devil’s Tail
*Giant Climbing Tearthumb
*Asiatic Smartweed

Thank you to Pennsylvania American Water for sponsoring the NPC blog during October!