is one of the taller-growing species in this large genus, reaching heights (and widths) of up to 2 feet. Plants branch readily; stems have short leaves around the base and at intervals most of the way to the tip. Stem leaves are alternate towards the base, becoming opposite higher up. Stems and calyces are covered by bristly hairs, pointing outwards, of different lengths, the longest greater than the stem diameter.
The tiny white, yellow-centered flowers are borne in curving, elongated clusters; each is about 1/8 of an inch in diameter, opening to five rounded lobes. Fruit divides into 4 narrow, brownish-black nutlets, lanceolate to ovate in shape, with a groove across one face. One nutlet is slightly longer than the other three.