Numer. List. 1. 1829.

Common names: Ray spiked fern
Etymology: Greek aktis, ray, and stachys, spike, referring to the rays of the fertile leaves
Treatment appears in FNA Volume 2.

Plants terrestrial. Roots dark, fibrous, covered with dark, stiff hairs, 2–3 mm. Stems upright; hairs uniseriate. Leaves all fertile (even youngest), unbranched, long-petioled. Blades falsely digitate, reduced to 2–many erect to spreading terminal rays; rays appearing to be whorled but actually borne on very short rachis. Sporangia in 2–4 rows. Gametophytes subterranean, not green, tuberlike, brown-hairy. x = 134, 140.


Nearly worldwide in tropical regions.


Species 20 (1 in the flora).