This introduced perennial plant is tufted at the base, producing multiple stems up to 1½' long, although they are usually about one-half of this length or less. These stems are ascending to widely spreading; they are green or purple, terete (round in cross-section), and pubescent. The opposite leaves are up to 1" long and 1/3" across (or a little larger); they are variably shaped, including lanceolate-ovate, oval-oblong, or broadly oblanceolate. The leaves are pubescent, smooth along the margins, and sessile at the base; they have a prominent central vein on the upper surface. The stems often terminate in small cymes (flat-headed clusters) of 1-5 small flowers; both the peduncles and pedicels of these cymes are pubescent. At the base of each cyme, there is a pair of leafy bracts with thin translucent margins. Each flower is up to ¼" across, consisting of 5 green sepals, 5 white petals with notched tips, 10 stamens with pale yellow anthers, and 5 styles; some plants may produce flowers with fewer than 10 stamens. The sepals are lanceolate, pubescent, and translucent along their margins; they are about the same length as the petals. The blooming period occurs intermittently from late spring to early fall and may last several months for individual plants. Each flower is replaced by a cylindrical seed capsule with 10 small teeth along its upper rim. Each seed capsule containing several small seeds. The seeds are somewhat flattened and minutely warty or pebbly. The root system is mostly fibrous. This plant reproduces primarily by reseeding itself; it can also form vegetative offsets when the nodes of the lower stems develop rootlets while lying on moist ground.