Cyanea maritae is a shrub growing 2–2.4 m tall, recognized by its distinctive juvenile and adult stages. Juvenile stems are unbranched and armed with numerous prickles. In contrast, adult stems are 0.7–1.5 cm in diameter at the apex, broadening to 6.3–7.4 cm at the base, and have 2 to 4 strongly ascending branches, sometimes remaining unbranched. Both stages feature white latex. The leaves are simple and alternate, with juvenile leaves broadly elliptic and adult leaves elliptic or oblong, featuring pinnately parted to divided margins with triangular to narrowly triangular segments. The surfaces are armed with prickles and range from dark to light green, sometimes pubescent on the veins. The inflorescences are arranged in racemes within the apical rosette, bearing 9 to 45 flowers over their lifetime but only 4 to 8 at a time. The hypanthium is campanulate or obconic, and the calyx has oblong lobes. The corolla is white-tinged, pink, zygomorphic (bilaterally symmetric), and sparsely pubescent. The staminal column is glabrous, and the anthers open by longitudinal slits. The ovary is inferior and 2-celled, with a 2-lobed stigma that becomes receptive after the style grows through the anther tube. The fruit is a yellowish orange berry, broadly ellipsoid or obovoid, with brown, broadly ellipsoid, shiny seeds, 0.5-0.7 mm long; 0.4-0.5 mm diameter, with a dicotyledonous embryo embedded in an oily endosperm. It grows in mesic forests at an elevation of approximately 855 meters.