Mare's tail, Hippuris vulgaris, is a different plant and grows in water.
From the irishtimes.com
She wages a perpetual war against mare's tail in her front garden and ground elder in the back.
From the gazetteherald.co.uk
Palms along a horse pasture rustle with the morning's first breeze, the swishing of a mare's tail mirroring the movement of the fronds.
From the edition.cnn.com
The eastern horizon glowed a vivid orange, and the high, wispy, mare's tail cirrus clouds incandesced gold against a sky of deep, brilliant blue.
From the chron.com
Should you be battling with sorrel, creeping buttercup, nettle, dock and mare's tail on your plot you will have a good indication that the soil is on the acid side.