Gleichenia Sm.

Rhizome dichotomously branched, protostelic, near the apex protected by peltate scales. Fronds of mature plants of indefinite growth in length (except sometimes at high altitudes), bearing primary branches in pairs, the apex of the main rachis dormant during the development of each pair of primary branches, the dormant apex in some cases protected by a pair of stipule-like leaflets of distinctive form (such stipular leaflets less often present in conjunction with dormant apices of lateral branch-systems); primary branches often each bearing a pair of secondary branches with a usually dormant apex between them, the process sometimes repeated to produce ultimate branches of fourth or fifth Orders; dormant apices protected by peltate scales which (with two exceptions) are fringed by outgrowths from the marginal cells; ultimate branches either simply pinnatifid or bipinnatifid; lamina in all cases lobed almost to the costa, the veins in each segment pinnately branched; lateral veins simple or once forked; costae, costules and veins when young protected by small fringed peltate scales and by stellate hairs, sometimes glabrescent when mature; sori one or several to each segment of the lamina, upon the lateral veins, not terminal upon them (on the acroscopic branch of a forked vein), exindusiate, each consisting of 2-5 large sporangia; paraphyses, in the form of small stellate hairs or small scales with long marginal hairs, often present with the sporangia; annulus complete and oblique, dehiscing dorsally. Spores monolete or trilete, smooth and translucent, 256 or more in each sporangium.