Schiedea laui is an erect to strongly ascending subshrub, growing to 50 to 150 cm. The stems are often swollen at the nodes, terete (cylindrical), 4-angled or -ridged, and many-branched. They are glabrous throughout, except for the bracts and sepals, and the internodes are lightly purple-tinged. A fibrous root system supports this plant. The leaves are simple and opposite, with narrowly ovate or lanceolate blades to narrowly or broadly elliptic, measuring 6.5 to 13 cm in length and 1.5 to 2.8 cm in width. The leaf apex ranges from acute to acuminate, and the base, often connate around the stem, gradually attenuates. The surfaces of the leaves are dull green, sometimes with a purple tinge, slightly thickened, rubbery, and chartaceous when dry, with only the midvein evident. The margins are entire, slightly thickened, and become revolute toward the base. The midvein is slightly eccentric. The petioles are 0.5 to 1.1 cm long and weakly grooved. Stipules are absent. The flowers form in a terminal inflorescence with 10 to 18 flowers on a structure measuring 17 to 26 cm long. It is diffuse and erect, with tertiary and higher-level internodes usually ascending or appressed. The pedicels are appressed at anthesis and sometimes have a few hairs toward the base. The flowers are bisexual (perfect) and cleistogamous. The sepals are 4.0 to 4.5 mm long, narrowly lanceolate, green, sometimes purple-tinged, opaque, glabrous on the abaxial side, with scarious (thin, dry), weakly ciliate margins. The corolla (petals) is absent. There are 10 stamens with dimorphic filaments and subequal pale yellow anthers. The superior ovary is 1-celled, with free-central ovule placentation and 3 to 4 styles. The fruit is a narrowly ovoid capsule, approximately 4.0 to 4.5 mm long. The seeds are about 1 mm long, orbicular-reniform, compressed, with starchy perisperm (nutritive tissue surrounding the embryo), and lack true endosperm. It inhabits wet montane forests between 1,100-1,146 meters.