Question

Which plant is described by these clues? Its genus name is the word a Roman naturalist used for sorrel, tied by one tradition to a verb meaning to suck, after the habit of chewing the sour leaves of its kin to ease thirst. Every stem joint is swollen and collared by a thin brown {ochrea}, a papery tube of fused {stipules} that tears as the shoot lengthens. The flowers have no petals whatever, just six greenish {tepals} in two ranks of three, shaken open by wind rather than visited by bees. A stout fleshy {taproot} drives as deep as 5 feet (1.5 m), bright yellow where it is cut, and throws up a fresh crown from any fragment left in the soil. As the seed ripens the inner three {tepals} enlarge into dry {valves} around a three-angled {achene}, two to five slender teeth lining their edges and one carrying a swollen corky grain. Chewed leaves turn sharply sour on the tongue from oxalic acid, pleasant in a mouthful and a hazard to grazing stock in quantity. Its basal blades are broad oblong things up to 14 inches (35 cm) long and 8 inches (20 cm) across, notched into a shallow heart shape where the stalk meets them. The specific epithet is Latin for blunt-leaved, recording a leaf tip that rounds off instead of tapering to a point. Native to Europe and western Asia, it has become a pasture, garden and roadside weed across most of North America, thriving on trampled fertile ground up to about 7,000 feet (2,100 m). A single plant can shed as many as 60,000 seeds in one season, and a few of them are still able to germinate after 80 years buried in the soil. Where it shares a pasture with a narrow-leaved cousin whose leaf margins curl tightly, the two hybridise and produce intermediates that defeat quick identification. Children across Britain and Ireland are taught to snatch this plant's big leaf and rub it on a nettle sting, a remedy roughly 2,000 years old and unsupported by evidence.

Accepted Answer

Rumex obtusifolius

Name That Plant #063