by Nathaniel Lord Britton & Addison Brown

“ Small terrestrial plants, with small, erect, fleshy, often tuberous, rootstocks bearing fibrous naked roots and 1-6 slender, erect leaves, these consisting usually of a short, cylindric common stalk, bearing at its summit a simple entire lanceolate to reniform sessile or short-stalked sterile blade with freely anastomosing veins and usually a single simple long-stalked spike, the sporophyl, formed of 2 rows of large coalescent sporanges ”

“ Leaves 1′–9′ long, slender, delicate and lax, shining, light or yellowish green, eventually decumbent and stramineous, the common stalk very long, usually more than half the length of the plant; buds rather small, the sporophyl erect, the tip of the sterile blade slightly inclined. Sterile blade short-stalked, simple, lobed, or usually with 1–3 pairs of distant, alternate, lunulate or cuneate, decurrent, usually entire segments, the apex emarginate; sporophyl short-stalked, simple or rarely a little branched, flattened, the large sporangia somewhat immersed in rows or groups on either side. ”

“ Succulent plants consisting of a short fleshy rootstock bearing one or several leaves and numerous fibrous often fleshy roots. Leaves erect or pendent, consisting of a simple, palmately or dichotomously lobed, pinnately compound or decompound, sessile or stalked, sterile blade, and one or several separate stalked fertile spikes or panicles (sporophyls) , borne on a common stalk. Sporanges formed from the interior tissues, naked, each opening by a transverse slit. ”