ABSTRACT

Perennial, terrestrial or epiphytic herbs. Rhizome short, usually erect; roots stout, fibrous, clustered. Fronds one to several arising from rhizome with new, undeveloped fronds contained in bud at sheathing base of last opened frond, erect or pendant, usually stalked or sessile, simple, lobed or variously com­ pound; lamina being either sterile, or with lateral or apparently ventral fertile segment. Fertile segment simple, racemose or paniculate. Sporangia bivalved, borne laterally either on surface of branches or imbedded in tissue of spike. Spores numerous, thick-walled Family of 3 cosmopolitan genera, all of which are represented in Sri Lanka.