Schiedea stellarioides is a weakly erect to sprawling subshrub, typically 30 to 60 cm tall, often multi-stemmed from the base and forming a dense clump. The stems, usually swollen at the nodes, are terete (cylindrical), 4-angled or -ridged, and branched. They are green, conspicuously 4-ridged, and compressed, especially the younger ones. The younger stems are moderately puberulent with crinkly to curved hairs, while the older stems become sparsely puberulent. The leaves are simple and opposite, with linear to oblong-elliptic blades measuring 2.5 to 8.2 cm in length and 0.2 to 1.3 cm in width. The apex is acute to acuminate, and the base gradually tapers and is sessile. The leaf surfaces are puberulent toward and on the margins on the upper side and the midvein on the lower side but otherwise glabrate. The leaves are slightly thickened and membranous, with entire and slightly revolute margins. The midvein is the only vein evident, and the petioles are weakly to conspicuously connate around the stem. Stipules are absent. The inflorescence is terminal, bearing 17 to 85 flowers and measuring 15 to 32 cm long. It is diffuse and weakly erect, with tertiary and higher-order internodes and pedicels ascending to weakly spreading. The flowers are bisexual (perfect) and usually pendent. The sepals are 2.8 to 3.6 mm long, lanceolate, green, tinged purple at the apex, along the midrib, and toward the base. The corolla (petals) is absent. There are 10 to 11 stamens with strongly dimorphic filaments and pale reddish-purple anthers. The superior ovary is 1-celled, with free-central ovule placentation and 3 to 4 styles. The fruit is an ovoid capsule, 2.4 to 3 mm long, containing 0.9 to 1.1 mm long seeds, orbicular-reniform, slightly rugose, with starchy perisperm (nutritive tissue surrounding the embryo), and no true endosperm. It grows in open, dry sites on cliffs and mesic forests between 300-1,220 meters.