All leaves are pubescent on upper and lower surfaces. Flowers are perfect and in racemosely arranged cymes axillary to the leaves or on terminating short branches, pedicellate, crowded at anthesis, less crowded in fruit. The throat of the corolla bears five hairy scales. Five stamens are inserted into the upper part of the tube. The pistil consists of a deeply lobed ovary and simple style.
Fruit is indehiscent and consists of one to four nutlets.
Hound's tongue is native to Eurasia and was introduced to North America as a contaminant of agricultural seed. It is now found over much of North America. It grows on rangeland, pastures, abandoned cropland, roadsides, and waste places. It colonizes easily and quickly forms dense monocultures on disturbed habitats. It can become established on rangelands and retard the reestablishment of valuable range species.