knotwood

But the upper part, on account of the great heat in it, throws up branches into the air through the knots; and this, when it is cut off about twenty feet from the ground and then hewn, is called "knotwood" because of its hardness and knottiness.

The Ten Books on Architecture Vitruvius Pollio

On the road sides you see broom, heather, heath, harebells, along with gorse and bracken with milkwort nestling underneath: crested dog's tail and sheep's fescue are common grasses, while spurrey, knotwood, corn marigold, are a few of the numerous weeds in the arable fields.

Lessons on Soil E. J. Russell

"Heraldic Crests for Invasive Species" are black-and-white letterpress prints featuring non-native animals that have invaded northern England: the European rabbit, the North American signal crayfish, and plants like Japanese knotwood and Himalayan balsam.

NYT > Home Page By MARTHA SCHWENDENER 2011