Phyllostegia electra is a nearly erect subshrub with stems densely covered in spreading or retrorsely short-hispidulous hairs, some of which are gland-tipped. The leaves are simple and opposite, with ovate to lanceolate blades measuring 9–15 cm in length and 2.5–5.6 cm in width. The apex is acuminate, and the base ranges from broadly cuneate to truncate. The upper leaf surfaces are sparsely hispidulous to glabrate and sparsely glandular-dotted, while the lower surfaces are moderately hispidulous along the veins and evenly glandular-dotted. The blades are membranous, with serrate-crenate to dentate-crenate margins. Petioles are densely hispidulous and 2.5–4 cm long. It features flowers in leafy, usually lax, compound, terminal, bracteate racemose inflorescences approximately 8–20 cm long, with pedicels 4–10 mm long, densely hispidulous, and often gland-tipped. The calyx is campanulate, 6–7 mm long, enlarging in fruit, with hispidulous veins and densely glandular-dotted. The corolla is bilabiate and white, with a tube roughly 14-15 mm long, short-hirtellous, and the lower lobe broadly ovate to suborbicular. It has four stamens, and the fruit consists of nutlets about 3 mm long, 1-seeded, dark green to black, drupaceous, and fleshy. The seeds lack an endosperm or are scanty and oily. It is found in mesic to wet forests between 610-1,485 meters.