Cyclosorus boydiae is a small to medium-sized fern with reclining or erect stems and a large, tangled mass of roots that form a holdfast. Fronds are stiffly upright, once-divided, usually 10 to 30 cm (4 to 12 in) long. Pinnae are lanceolate, 2 to 3.5 cm (0.8 to 1.4 in) long with obtuse tips.