knotgrass
nounA low-growing, weedy grass (Paspalum distichum) with spikelets arranged in two rows along the rachis.
nounAny of several weedy plants of the genus Polygonum having stems with nodes.
nounA weed of almost world-wide distribution, Polygonum aviculare: so called from the numerous nodes in its stems and its thickly spreading habit.
nounBy extension, any plant of the genus Polygonum, properly knotweed.
nounIn occasional use, a plant of some other genus more or less similar.
nounCouch-grass: a use of doubtful appropriateness.
nouna common weed with jointed stems
The dog grass. See under
An