Myrsine knudsenii, in the Primulaceae (primrose) family, is a small branched tree or shrub 1.5 to 4.5 m (5 to 15 ft) tall, with pale to dark brown, tortuous branches. Leaves are dark green, with young leaves dark purplish red, somewhat clustered toward the tips of the branches, roughly elliptical, 4.5 to 8.5 cm (1.8 to 3.4 in) long, and 3.0 to 4.7 cm (1.2 to 1.9 in) wide, with a prominent midrib. Flowers are apparently perfect, with 5 to 12.7 cm (2 to 5 in) bundles arising on short woody knobs below and occasionally among the leaves, with cream-colored petals that are sparsely ciliolate (covered with minute hairs), 3.5 to 4.2 mm (0.1 to 0.2 in) long. Fruits are drupes, dark purple, 5 to 8 mm (0.2 to 0.3 in) long, with a single large seed.